题目 ：Problem - 2035 (hdu.edu.cn)
#include<bits/stdc++.h>
using namespace std;
#define LL long long
int qp(LL a, LL b, int mod){int res = 1;while(b){if(b&1) res = res*a%mod;a = a*a%mod;b >>= 1;}return res;
}
int main(){int a,b;while (scanf("%d %d",&a,&b)!=EOF&&(a!=0&&b!=0)){printf("%d\n",qp(a,b,1000));}return 0;
}