#include<stdio.h>
int main  (){
  long int N;
  long int ans = 1;
  long int a = 1000000000000000000;
  scanf("%ld",&N);
  long int A[N];
  for(int i=0;i<N;i++){
    
    scanf("%ld",& A[i]);
    ans = A[i]*ans;
  }
  if(ans>a){
      printf("-1");
  }else{
          printf("%ld", ans);  
  }


      
  return 0;
}