#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <math.h>
#include <time.h>
#define ll long long
#define min(a, b) ((a) > (b) ? (b) : (a))
#define max(a, b) ((a) > (b) ? (a) : (b))
#define miin(a, b, c) min((a), min((b), (c)))
#define maax(a, b, c) max((a), max((b), (c)))
#define mod 1000000007

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