C++ :

#include <cstdio>
using namespace std;
long long fx(long long,long long,long long);
int main()
{
    long long a,b,c;
    scanf("%lld%lld%lld",&a,&b,&c);
    printf("%lld^%lld mod %lld=%lld",a,b,c,fx(a,b,c));
    return 0;
}
long long fx(long long a,long long n,long long m)
{
    long long r=1,t=a;
    while(n>0)
    {
        if(n%2)
            r=(r*t)%m;
        n/=2;
        t=(t*t)%m;
    }
    return r;
}