import java.util.*;

class Student

{

String name;

int id;

String dept;

Student(String name,int id,String dept)

{

this.name=name;

this.id=id;

this.dept=dept;

}

}

class Department

{

List<Student> student;

String name;

Department(String name,List<Student> student)

{

this.name=name;

this.student=student;

}

List<Student> getStudent()

{

return student;

}

}

class Institute

{

List<Department> dept;

String name;

Institute(String name,List<Department> dept)

{

this.name=name;

this.dept=dept;

}

int getTotalStudentInInstitute()

{

int noOfStudent=0;

List<Student> student;

for(Department d:dept)

{

student=d.getStudent();

for(Student s:student)

{

noOfStudent++;

}

}

return noOfStudent;

}

}

class Agression

{

public static void main(String args[])

{

Student s1=new Student("gaurav",153,"CSE");

Student s2=new Student("Kushal",156,"CSE");

Student s3=new Student("vikash",253,"MECH");

Student s4=new Student("Ankit",254,"MECH");

List<Student> cse=new ArrayList<>();

cse.add(s1);

cse.add(s2);

List<Student> mech=new ArrayList<>();

mech.add(s2);

mech.add(s3);

Department d1=new Department("CSE",cse);

Department d2=new Department("MECH",mech);

List<Department> dept=new ArrayList<>();

dept.add(d1);

dept.add(d2);

Institute ins=new Institute("NIT",dept);

System.out.println("Total Studnet in institute="+ins.getTotalStudentInInstitute());

}

}