#include <stdio.h>
long long a [100010];
int main (){
  int n;
  scanf("%d",&n);
  for(int i=0;i<n;i++) scanf("%lld",&a[i]);
  int zero =0;
  for(int i=0;i<n;i++)if(a[i]==0) zero ++;
  if(zero >0){
  // a[i] contains 0
    printf("0\n");
    return 0;
  }
  long long prod =1;
  for(int i=0;i<n;i++){
    if(a[i ] <=1000000000000000000/ prod ){
      // This condition is equivalent to prod*a[i] <=10ˆ18
      prod *=a[i];
    }else{
    printf("-1\n");
    return 0;
    }
  }
  printf("%lld\n",prod );
}