#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)
		{
			printf("0\n");
			return 0;
		}
	long long sum = 1;
	for (int i = 0; i < n; i++)
	{
		if (a[i] <= 1000000000000000000/sum)
			sum *= a[i];
		else
		{
			printf("-1\n");
			return 0;
		}
	}
	printf("%lld\n", sum);
}
