#include<iostream>
#include<algorithm>
using namespace std;
int main(){
    long long n,a[100010]={},ans=1;cin>>n;
    for(int c=1;c<=n;c++)cin>>a[c];
    sort(a+1,a+n+1);
    if(a[1]==0)cout<<"0\n";
    else{
        for(int c=1;c<=n;c++){
            ans*=a[c];
            if(ans>1e18||ans<0){
                cout<<"-1\n";return 0;
            }
        }cout<<ans<<"\n";
    }
}

WA on #1.