#include <stdio.h>

int main()
{int a,i;
scanf("%d",&a);
unsigned long long b[100000],c;
c=1;
for(i=0;i<a;i++){
    scanf("%llu",b[i]);
    if(b[i]==0){printf("0");return 0;}
    if(c*b[i]>1e+18){printf("-1");return 0;
                        }
        c=c*b[i];}
 return 0;
}