#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned int UI;

ll read(){
    ll sgn=0,x=0;
    char c=getchar();
    while(!isdigit(c)) sgn|=(c=='-'),c=getchar();
    while(isdigit(c)) x=x*10+c-'0',c=getchar();
    return sgn?-x:x;
}

const int Lim=1e9;

int main(){

    ll a=read(),b=read();

    if(a==1){
        puts("1");
        return 0;
    }

    ll s=1;
    while(b--){
        s*=a;
        if(s>Lim){
            puts("-1");
            return 0;
        }
    }

    printf("%lld",s);

    return 0;
}