hdu 6063 RXD and math

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll mod=1e9+7;

ll hh(ll x,ll y){
    ll s=1;
    while(y){
        if(y&1) s=s*x%mod;
        x=x*x%mod;
        y>>=1;
    }
    return s;
}
int main(){
    int k=1;
    ll n,m;
    while(scanf("%lld%lld",&n,&m)!=EOF){
        n%=mod;
        printf("Case #%d: %lld\n",k++,hh(n,m));
    }
}