find last 4 digit of (x^y) --- x and y are long long

last_4_digits.cpp

#include<bits/stdc++.h>
using namespace std;
int main()
{



    long long pow=1;
    long long n=1;
    while(cin >> n >> pow && pow && n)
    {
        long long res=1;

        for(long long i=0; i<pow; i++)
        {
            res*=n;
            res=res%10000; /// 10000 - 4 zero for last four digits
            ///for 5 digits use 100000

        }

        cout << res << endl;

    }


    return 0;
}