text: //function is block of code used for do specific task
  /* syntax of fucntion
  returntype functionname(parametere1,parameter2)
  {
  
      //body of fucntions
  }
  */
  //program to write funtion of add 2 integer.
  #include<iostream>
  using namespace std;
  int summation(int n1, int n2){
      int sum=n1+n2;
  }
   int main()
   {
       int n1,n2;
       cin>>n1>>n2;
       cout<<summation(n1,n2)<<endl;
       return 0;
   }
   //Concept of call stack is the very important concept in the memory
   //fibannaci series- it a sequence in which next term is the sum of previous two terms
   //program to print fibonacci series
   
  #include<iostream>
   using namespace std;
   void fib(int n){
       int t1=0;
       int t2=1;
       int nextterm;
       for(int i=1; i<=n; i++){
           cout<<t1<<endl;
           nextterm=t1+t2;
           t1=t2;
           t2=nextterm;
       }
   }
   int main()
   {
       int n;
       cin>>n;
        fib(n);
        return 0;
   }
   //program for factorial of numbers.
  #include<iostream>
   using namespace std;
   int fact(int n){
       int factorial=1;
       for(int i=2;i<=n; i++){
           factorial*=i;
       }
       return factorial;
       
   }
   int main()
   {
       int n;
       cin>>n;
      int ans=fact(n);
      cout<<ans<<endl;
        return 0;
   }
   //Hackerrank program
  #include <cmath>
  #include <cstdio>
  #include <vector>
  #include <iostream>
  #include <algorithm>
  using namespace std;
  void great(int a, int b,int c,int d){
      if(a>b && a>c &&a>d){
          cout<<a<<endl;
      }
      else if (b>a && b>c && b>d) {
       cout<<b<<endl;
      }
      else if(c>a && c>b  && c>d){
             cout<<c<<endl;
      }
      else {
      cout<<d<<endl;
      }
  };    
  
  
  int main() {
     int a,b,c,d;
     cin>>a>>b>>c>>d;
     great(a,b,c,d);
      return 0;
  }
  