#include <stdio.h>
	int main (){
		
	int n; 	
	scanf("%d",&n);
		long long int arr[n], max=1e18, prod=1, flag=0, zero=0;
		
	for (int i =0;i<n;++i){
	
	scanf ("%lld", &arr[i]);
	 flag= (arr[i]> max)? 1:flag;
	 prod*=arr[i];	
	(arr[i]) ? max/=arr[i]:zero=1;	
		
	}
	(zero)? puts ("0"):((flag) ? puts("-1"): printf("%lld\n",prod));
	
	
	
	
	return 0;
	}