#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);
}
