C :

#include <stdio.h>
int main()
{
	int m,n;
	int total;
	while(scanf("%d %d",&m,&n))
	{
		if(m==0&&n==0)
		break;
		total=1;
		while(n--)
		{
			total=total*m%10000;
		}
		printf("%04d\n",total);
	}
}

C++ :

#include<stdio.h>

int main(){
	int a, b;
	while(scanf("%d%d", &a, &b) != EOF){
		if(a == 0 && b == 0){
			return 0;
		}
		int ans = 1;
		for(int i = 0; i < b; i++){
			ans = (((a % 1000) * (ans % 1000)) + 1000) % 1000;
		}
		printf("%04d\n", ans);
	}
}

Python :

# coding=utf-8
while True:
    m, n = map(int, input().split())
    if m == 0 and n == 0:
        break
    total = 1
    for _ in range(n):
        total = (total * m) % 10000
    print(f"{total:04d}")