#include <bits/stdc++.h>
using namespace std;
#define int long long

const int MAX = 1e18;

signed main(){
    int n;
    cin>>n;
    int m = 1;
    int arr[n+10];
    bool ohno = false;
    for(int i=0; i<n; i++){
        cin>>arr[i];
    }
    sort(arr,arr+n);
    if(arr[0] == 0 ){
        cout << 0 << endl;
        return 0;
    }
    for(int i=0; i<n; i++){
        if(m > MAX/arr[i]){
            ohno = true;
            break;
        }   
        m *= arr[i];
    }
    if(ohno){
        cout<< -1 <<endl;
    }else{
        cout << m <<endl;
    }
}