
#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); 
}