#include<bits/stdc++.h>
using namespace std;
long long int ans=0,n,m;
int main(){
    cin>>n>>m;
    ans=n;
    for(long long int i=1;i<m;i++){
         
        n*=ans;
        if(n>1000000000){
            cout<<-1;
         
            return 0;
        }
    }
    cout<<n;
}
/**************************************************************
	Problem: 2405
	User: linzihang
	Language: C++
	Result: Accepted
	Time:983 ms
	Memory:2072 kb
****************************************************************/