#include<bits/stdc++.h>
#define rep(x,y,z) for(int x=y;x<=z;x++)
#define drep(x,y,z) for(int x=y;x>=z;x--)
#define ull unsigned long long
#define ll long long
using namespace std;
inline int read()
{
	int x=0;bool flag=1;char ch=getchar();
	while(ch<'0'||ch>'9') {if(ch=='-')flag=0;ch=getchar();}
	while(ch>='0'&&ch<='9') {x=(x<<3)+(x<<1)+ch-'0';ch=getchar();}
	if(flag) return x;
	return ~(x-1);
} 
inline void write(int x)
{
	if(x<0) {x=~(x-1);putchar('-');}
	if(x>9) write(x/10);
	putchar(x%10+'0');
}
///////////////////////
const ull mx=1e9;
const ull on=1;
ull a,b;
ull c,ans;
int main()
{
    freopen("csp2022pj_pow.in","r",stdin);
	freopen("csp2022pj_pow.out","w",stdout);
    cin>>a>>b;
    ans=1;
    c=a;
    if(b&1) ans=c;
    for(int i=1;(on<<i)<=b;i++)
    {
		c*=c;
    	if(c>mx)
    	{
    		ans=0;
    		break;
		}
		if(b&(on<<i)) ans*=c;
		if(ans>mx)
		{
			ans=0;
			break;
		}
	}
	if(!ans) cout<<"-1\n";
	else cout<<ans<<endl;
    return 0;
}