#include <bits/stdc++.h>

int main() {
	freopen("csp2022pj_pow.in","r",stdin);
	freopen("csp2022pj_pow.out","w",stdout);
	int a,b;
	std::cin >> a >> b;
	if(a == 1) {
		std::cout << 1 << std::endl;
		return 0;
	}
	int cnt = 0;
	for(int x = 1e9;x;x /= a)++ cnt;
	if(b >= cnt) {
		std::cout << -1 << std::endl;
		return 0;
	}
	long long ans = 1;
	for(int i = 1;i <= b;++ i)ans = 1ll * ans * a;
	if(ans > 1e9)std::cout << -1 << std::endl;
	else std::cout << ans << std::endl;
	return 0;
}