#include <stdio.h>
int main(void)
{
	unsigned long long int num, sum=1;
	int lim, i;
    int flag1=0, flag2=0;
	scanf("%d", &lim);
	for (i = 0; i < lim; i++) {
		scanf("%lld", &num);
        if(num  > 1000000000000000000)
          flag1 = 1;
        if(num <= 1000000000000000000 / sum)
          sum *= num;
        if(num ==0)
          flag2=1;
	}
	if (flag2==1)
		printf("%d\n", 0);
	else if(flag1==1)
		printf("%d\n", -1);
    else 
        printf("%lld\n", sum);
	return 0;
}