diff --git a/contributing3md.py b/contributing3md.py
new file mode 100644
index 000000000000..705fdd5540d7
--- /dev/null
+++ b/contributing3md.py
@@ -0,0 +1,621 @@
+"""
+Student Management System
+A comprehensive system for managing student records, grades, attendance, and courses.
+"""
+
+import json
+import os
+import datetime
+from typing import List, Dict, Optional
+import random
+import string
+
+
+class Student:
+    """Represents a student with personal information and academic records."""
+
+    def __init__(
+        self, student_id: str, name: str, email: str, age: int, phone: str, address: str
+    ):
+        self.student_id = student_id
+        self.name = name
+        self.email = email
+        self.age = age
+        self.phone = phone
+        self.address = address
+        self.enrolled_courses = []
+        self.grades = {}
+        self.attendance = {}
+        self.created_at = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S")
+
+    def to_dict(self) -> Dict:
+        """Convert student object to dictionary."""
+        return {
+            "student_id": self.student_id,
+            "name": self.name,
+            "email": self.email,
+            "age": self.age,
+            "phone": self.phone,
+            "address": self.address,
+            "enrolled_courses": self.enrolled_courses,
+            "grades": self.grades,
+            "attendance": self.attendance,
+            "created_at": self.created_at,
+        }
+
+    @classmethod
+    def from_dict(cls, data: Dict) -> "Student":
+        """Create student object from dictionary."""
+        student = cls(
+            data["student_id"],
+            data["name"],
+            data["email"],
+            data["age"],
+            data["phone"],
+            data["address"],
+        )
+        student.enrolled_courses = data.get("enrolled_courses", [])
+        student.grades = data.get("grades", {})
+        student.attendance = data.get("attendance", {})
+        student.created_at = data.get("created_at", student.created_at)
+        return student
+
+    def enroll_course(self, course_id: str) -> bool:
+        """Enroll student in a course."""
+        if course_id not in self.enrolled_courses:
+            self.enrolled_courses.append(course_id)
+            self.grades[course_id] = []
+            self.attendance[course_id] = {"present": 0, "absent": 0}
+            return True
+        return False
+
+    def add_grade(self, course_id: str, grade: float, assignment: str) -> bool:
+        """Add a grade for a specific course."""
+        if course_id in self.enrolled_courses:
+            self.grades[course_id].append(
+                {
+                    "grade": grade,
+                    "assignment": assignment,
+                    "date": datetime.datetime.now().strftime("%Y-%m-%d"),
+                }
+            )
+            return True
+        return False
+
+    def mark_attendance(self, course_id: str, status: str) -> bool:
+        """Mark attendance for a course."""
+        if course_id in self.enrolled_courses and status in ["present", "absent"]:
+            self.attendance[course_id][status] += 1
+            return True
+        return False
+
+    def get_average_grade(self, course_id: str) -> Optional[float]:
+        """Calculate average grade for a course."""
+        if course_id in self.grades and self.grades[course_id]:
+            grades = [g["grade"] for g in self.grades[course_id]]
+            return sum(grades) / len(grades)
+        return None
+
+    def get_attendance_percentage(self, course_id: str) -> Optional[float]:
+        """Calculate attendance percentage for a course."""
+        if course_id in self.attendance:
+            present = self.attendance[course_id]["present"]
+            absent = self.attendance[course_id]["absent"]
+            total = present + absent
+            if total > 0:
+                return (present / total) * 100
+        return None
+
+
+class Course:
+    """Represents a course with details and enrolled students."""
+
+    def __init__(
+        self, course_id: str, name: str, instructor: str, credits: int, description: str
+    ):
+        self.course_id = course_id
+        self.name = name
+        self.instructor = instructor
+        self.credits = credits
+        self.description = description
+        self.enrolled_students = []
+        self.schedule = {}
+
+    def to_dict(self) -> Dict:
+        """Convert course object to dictionary."""
+        return {
+            "course_id": self.course_id,
+            "name": self.name,
+            "instructor": self.instructor,
+            "credits": self.credits,
+            "description": self.description,
+            "enrolled_students": self.enrolled_students,
+            "schedule": self.schedule,
+        }
+
+    @classmethod
+    def from_dict(cls, data: Dict) -> "Course":
+        """Create course object from dictionary."""
+        course = cls(
+            data["course_id"],
+            data["name"],
+            data["instructor"],
+            data["credits"],
+            data["description"],
+        )
+        course.enrolled_students = data.get("enrolled_students", [])
+        course.schedule = data.get("schedule", {})
+        return course
+
+    def add_student(self, student_id: str) -> bool:
+        """Add a student to the course."""
+        if student_id not in self.enrolled_students:
+            self.enrolled_students.append(student_id)
+            return True
+        return False
+
+    def remove_student(self, student_id: str) -> bool:
+        """Remove a student from the course."""
+        if student_id in self.enrolled_students:
+            self.enrolled_students.remove(student_id)
+            return True
+        return False
+
+    def set_schedule(self, day: str, time: str) -> None:
+        """Set course schedule."""
+        self.schedule[day] = time
+
+
+class StudentManagementSystem:
+    """Main system for managing students and courses."""
+
+    def __init__(self, data_file: str = "student_data.json"):
+        self.data_file = data_file
+        self.students: Dict[str, Student] = {}
+        self.courses: Dict[str, Course] = {}
+        self.load_data()
+
+    def generate_id(self, prefix: str = "STU") -> str:
+        """Generate a unique ID."""
+        random_str = "".join(random.choices(string.digits, k=6))
+        return f"{prefix}{random_str}"
+
+    def add_student(
+        self, name: str, email: str, age: int, phone: str, address: str
+    ) -> str:
+        """Add a new student to the system."""
+        student_id = self.generate_id("STU")
+        while student_id in self.students:
+            student_id = self.generate_id("STU")
+
+        student = Student(student_id, name, email, age, phone, address)
+        self.students[student_id] = student
+        self.save_data()
+        return student_id
+
+    def add_course(
+        self, name: str, instructor: str, credits: int, description: str
+    ) -> str:
+        """Add a new course to the system."""
+        course_id = self.generate_id("CRS")
+        while course_id in self.courses:
+            course_id = self.generate_id("CRS")
+
+        course = Course(course_id, name, instructor, credits, description)
+        self.courses[course_id] = course
+        self.save_data()
+        return course_id
+
+    def enroll_student_in_course(self, student_id: str, course_id: str) -> bool:
+        """Enroll a student in a course."""
+        if student_id in self.students and course_id in self.courses:
+            student = self.students[student_id]
+            course = self.courses[course_id]
+
+            if student.enroll_course(course_id) and course.add_student(student_id):
+                self.save_data()
+                return True
+        return False
+
+    def add_grade(
+        self, student_id: str, course_id: str, grade: float, assignment: str
+    ) -> bool:
+        """Add a grade for a student in a course."""
+        if student_id in self.students:
+            if self.students[student_id].add_grade(course_id, grade, assignment):
+                self.save_data()
+                return True
+        return False
+
+    def mark_attendance(self, student_id: str, course_id: str, status: str) -> bool:
+        """Mark attendance for a student in a course."""
+        if student_id in self.students:
+            if self.students[student_id].mark_attendance(course_id, status):
+                self.save_data()
+                return True
+        return False
+
+    def get_student(self, student_id: str) -> Optional[Student]:
+        """Get a student by ID."""
+        return self.students.get(student_id)
+
+    def get_course(self, course_id: str) -> Optional[Course]:
+        """Get a course by ID."""
+        return self.courses.get(course_id)
+
+    def search_students(self, query: str) -> List[Student]:
+        """Search students by name or ID."""
+        results = []
+        query = query.lower()
+        for student in self.students.values():
+            if (
+                query in student.name.lower()
+                or query in student.student_id.lower()
+                or query in student.email.lower()
+            ):
+                results.append(student)
+        return results
+
+    def search_courses(self, query: str) -> List[Course]:
+        """Search courses by name or instructor."""
+        results = []
+        query = query.lower()
+        for course in self.courses.values():
+            if (
+                query in course.name.lower()
+                or query in course.instructor.lower()
+                or query in course.course_id.lower()
+            ):
+                results.append(course)
+        return results
+
+    def get_student_report(self, student_id: str) -> Optional[Dict]:
+        """Generate a comprehensive report for a student."""
+        student = self.get_student(student_id)
+        if not student:
+            return None
+
+        report = {
+            "student_info": {
+                "id": student.student_id,
+                "name": student.name,
+                "email": student.email,
+                "age": student.age,
+                "phone": student.phone,
+            },
+            "courses": [],
+        }
+
+        for course_id in student.enrolled_courses:
+            course = self.get_course(course_id)
+            if course:
+                avg_grade = student.get_average_grade(course_id)
+                attendance_pct = student.get_attendance_percentage(course_id)
+
+                report["courses"].append(
+                    {
+                        "course_id": course_id,
+                        "course_name": course.name,
+                        "instructor": course.instructor,
+                        "average_grade": round(avg_grade, 2) if avg_grade else "N/A",
+                        "attendance": f"{round(attendance_pct, 2)}%"
+                        if attendance_pct
+                        else "N/A",
+                        "grades": student.grades.get(course_id, []),
+                    }
+                )
+
+        return report
+
+    def get_course_statistics(self, course_id: str) -> Optional[Dict]:
+        """Get statistics for a course."""
+        course = self.get_course(course_id)
+        if not course:
+            return None
+
+        total_students = len(course.enrolled_students)
+        all_grades = []
+        all_attendance = []
+
+        for student_id in course.enrolled_students:
+            student = self.get_student(student_id)
+            if student:
+                avg_grade = student.get_average_grade(course_id)
+                if avg_grade:
+                    all_grades.append(avg_grade)
+
+                attendance = student.get_attendance_percentage(course_id)
+                if attendance:
+                    all_attendance.append(attendance)
+
+        stats = {
+            "course_id": course_id,
+            "course_name": course.name,
+            "instructor": course.instructor,
+            "total_students": total_students,
+            "average_grade": round(sum(all_grades) / len(all_grades), 2)
+            if all_grades
+            else "N/A",
+            "average_attendance": round(sum(all_attendance) / len(all_attendance), 2)
+            if all_attendance
+            else "N/A",
+        }
+
+        return stats
+
+    def delete_student(self, student_id: str) -> bool:
+        """Delete a student from the system."""
+        if student_id in self.students:
+            student = self.students[student_id]
+
+            # Remove from enrolled courses
+            for course_id in student.enrolled_courses:
+                course = self.get_course(course_id)
+                if course:
+                    course.remove_student(student_id)
+
+            del self.students[student_id]
+            self.save_data()
+            return True
+        return False
+
+    def delete_course(self, course_id: str) -> bool:
+        """Delete a course from the system."""
+        if course_id in self.courses:
+            course = self.courses[course_id]
+
+            # Remove from enrolled students
+            for student_id in course.enrolled_students:
+                student = self.get_student(student_id)
+                if student and course_id in student.enrolled_courses:
+                    student.enrolled_courses.remove(course_id)
+                    if course_id in student.grades:
+                        del student.grades[course_id]
+                    if course_id in student.attendance:
+                        del student.attendance[course_id]
+
+            del self.courses[course_id]
+            self.save_data()
+            return True
+        return False
+
+    def save_data(self) -> None:
+        """Save all data to JSON file."""
+        data = {
+            "students": {sid: s.to_dict() for sid, s in self.students.items()},
+            "courses": {cid: c.to_dict() for cid, c in self.courses.items()},
+        }
+
+        with open(self.data_file, "w") as f:
+            json.dump(data, f, indent=4)
+
+    def load_data(self) -> None:
+        """Load data from JSON file."""
+        if os.path.exists(self.data_file):
+            try:
+                with open(self.data_file, "r") as f:
+                    data = json.load(f)
+
+                self.students = {
+                    sid: Student.from_dict(s)
+                    for sid, s in data.get("students", {}).items()
+                }
+                self.courses = {
+                    cid: Course.from_dict(c)
+                    for cid, c in data.get("courses", {}).items()
+                }
+            except Exception as e:
+                print(f"Error loading data: {e}")
+                self.students = {}
+                self.courses = {}
+
+
+def print_menu():
+    """Display the main menu."""
+    print("\n" + "=" * 50)
+    print("STUDENT MANAGEMENT SYSTEM".center(50))
+    print("=" * 50)
+    print("1.  Add Student")
+    print("2.  Add Course")
+    print("3.  Enroll Student in Course")
+    print("4.  Add Grade")
+    print("5.  Mark Attendance")
+    print("6.  Search Students")
+    print("7.  Search Courses")
+    print("8.  View Student Report")
+    print("9.  View Course Statistics")
+    print("10. List All Students")
+    print("11. List All Courses")
+    print("12. Delete Student")
+    print("13. Delete Course")
+    print("0.  Exit")
+    print("=" * 50)
+
+
+def main():
+    """Main function to run the student management system."""
+    sms = StudentManagementSystem()
+
+    while True:
+        print_menu()
+        choice = input("\nEnter your choice: ").strip()
+
+        if choice == "1":
+            print("\n--- Add New Student ---")
+            name = input("Name: ")
+            email = input("Email: ")
+            age = int(input("Age: "))
+            phone = input("Phone: ")
+            address = input("Address: ")
+
+            student_id = sms.add_student(name, email, age, phone, address)
+            print(f"✓ Student added successfully! ID: {student_id}")
+
+        elif choice == "2":
+            print("\n--- Add New Course ---")
+            name = input("Course Name: ")
+            instructor = input("Instructor: ")
+            credits = int(input("Credits: "))
+            description = input("Description: ")
+
+            course_id = sms.add_course(name, instructor, credits, description)
+            print(f"✓ Course added successfully! ID: {course_id}")
+
+        elif choice == "3":
+            print("\n--- Enroll Student in Course ---")
+            student_id = input("Student ID: ")
+            course_id = input("Course ID: ")
+
+            if sms.enroll_student_in_course(student_id, course_id):
+                print("✓ Student enrolled successfully!")
+            else:
+                print("✗ Enrollment failed. Check IDs.")
+
+        elif choice == "4":
+            print("\n--- Add Grade ---")
+            student_id = input("Student ID: ")
+            course_id = input("Course ID: ")
+            grade = float(input("Grade (0-100): "))
+            assignment = input("Assignment Name: ")
+
+            if sms.add_grade(student_id, course_id, grade, assignment):
+                print("✓ Grade added successfully!")
+            else:
+                print("✗ Failed to add grade.")
+
+        elif choice == "5":
+            print("\n--- Mark Attendance ---")
+            student_id = input("Student ID: ")
+            course_id = input("Course ID: ")
+            status = input("Status (present/absent): ").lower()
+
+            if sms.mark_attendance(student_id, course_id, status):
+                print("✓ Attendance marked successfully!")
+            else:
+                print("✗ Failed to mark attendance.")
+
+        elif choice == "6":
+            print("\n--- Search Students ---")
+            query = input("Search query: ")
+            results = sms.search_students(query)
+
+            if results:
+                print(f"\nFound {len(results)} student(s):")
+                for student in results:
+                    print(
+                        f"  ID: {student.student_id} | Name: {student.name} | Email: {student.email}"
+                    )
+            else:
+                print("No students found.")
+
+        elif choice == "7":
+            print("\n--- Search Courses ---")
+            query = input("Search query: ")
+            results = sms.search_courses(query)
+
+            if results:
+                print(f"\nFound {len(results)} course(s):")
+                for course in results:
+                    print(
+                        f"  ID: {course.course_id} | Name: {course.name} | Instructor: {course.instructor}"
+                    )
+            else:
+                print("No courses found.")
+
+        elif choice == "8":
+            print("\n--- Student Report ---")
+            student_id = input("Student ID: ")
+            report = sms.get_student_report(student_id)
+
+            if report:
+                print(f"\n{'=' * 50}")
+                print(f"Student: {report['student_info']['name']}")
+                print(f"ID: {report['student_info']['id']}")
+                print(f"Email: {report['student_info']['email']}")
+                print(f"{'=' * 50}")
+
+                if report["courses"]:
+                    for course_info in report["courses"]:
+                        print(f"\nCourse: {course_info['course_name']}")
+                        print(f"  Instructor: {course_info['instructor']}")
+                        print(f"  Average Grade: {course_info['average_grade']}")
+                        print(f"  Attendance: {course_info['attendance']}")
+                else:
+                    print("\nNo courses enrolled.")
+            else:
+                print("Student not found.")
+
+        elif choice == "9":
+            print("\n--- Course Statistics ---")
+            course_id = input("Course ID: ")
+            stats = sms.get_course_statistics(course_id)
+
+            if stats:
+                print(f"\n{'=' * 50}")
+                print(f"Course: {stats['course_name']}")
+                print(f"Instructor: {stats['instructor']}")
+                print(f"Total Students: {stats['total_students']}")
+                print(f"Average Grade: {stats['average_grade']}")
+                print(f"Average Attendance: {stats['average_attendance']}%")
+                print(f"{'=' * 50}")
+            else:
+                print("Course not found.")
+
+        elif choice == "10":
+            print("\n--- All Students ---")
+            if sms.students:
+                for student in sms.students.values():
+                    print(
+                        f"ID: {student.student_id} | Name: {student.name} | Courses: {len(student.enrolled_courses)}"
+                    )
+            else:
+                print("No students in system.")
+
+        elif choice == "11":
+            print("\n--- All Courses ---")
+            if sms.courses:
+                for course in sms.courses.values():
+                    print(
+                        f"ID: {course.course_id} | Name: {course.name} | Students: {len(course.enrolled_students)}"
+                    )
+            else:
+                print("No courses in system.")
+
+        elif choice == "12":
+            print("\n--- Delete Student ---")
+            student_id = input("Student ID: ")
+            confirm = input(
+                f"Are you sure you want to delete student {student_id}? (yes/no): "
+            )
+
+            if confirm.lower() == "yes":
+                if sms.delete_student(student_id):
+                    print("✓ Student deleted successfully!")
+                else:
+                    print("✗ Student not found.")
+
+        elif choice == "13":
+            print("\n--- Delete Course ---")
+            course_id = input("Course ID: ")
+            confirm = input(
+                f"Are you sure you want to delete course {course_id}? (yes/no): "
+            )
+
+            if confirm.lower() == "yes":
+                if sms.delete_course(course_id):
+                    print("✓ Course deleted successfully!")
+                else:
+                    print("✗ Course not found.")
+
+        elif choice == "0":
+            print("\nThank you for using Student Management System!")
+            break
+
+        else:
+            print("\n✗ Invalid choice. Please try again.")
+
+        input("\nPress Enter to continue...")
+
+
+if __name__ == "__main__":
+    main()