#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;
9
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); }