Coodechef Dividing Stamps Problem Code: DIVIDING Solution

Solution in C++:
///**********ALLAH IS ALMIGHTY************///
///AH Tonmoy
///Department of CSE,23rd batch
///Islamic University,Bangladesh

#include<iostream>
using namespace std;
int main()
{
    int n,s=0,i,a,v;
    while(cin>>n)
    {
        s=0;
        for(i=1; i<=n; i++)
        {
            cin>>a;
            s=s+a;
        }

        v=(n*(n+1))/2;
        if(v==s)
            cout<<"YES"<<endl;
        else
            cout<<"NO"<<endl;
    }
    return 0;
}