#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;
2
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);
}