人见人爱A^B

#include<cstdio>
//快速幂
int powermod(int a,int b)
{
    int ans=1;
    a=a%1000;
    if(a==0) return 0;
    while(b)
    {
        if(b%2==1)
        ans=ans*a%1000;
        a=a*a%1000;
        b/=2;
    }
    return ans;
}
int main()
{
    int a,b;
    while(scanf("%d%d",&a,&b)!=-1)
    {
        if(!a&&!b) break;
        printf("%d\n",powermod(a,b));
    }
    return 0;
}