#include<stdio.h>

int main(){
    int n;
    scanf("%d",&n);
    long long a[n+1],sum=1;
    for(int i=0;i<n;i++){
        scanf("%lld",&a[i]);
        sum=sum*a[i];
        if(sum>=1000000000000000000){
            printf("-1\n");
            return 0;
        }
    }
    printf("%d\n",sum);
}