D_Currency_System_in_Geraldion.cpp

#include <bits/stdc++.h>

using namespace std;

int main() {
    int n;
    cin >> n;
    bool foundOne = false;
    int x;
    for (int i = 0; i < n; i++)
    {
     cin >> x;
     if(x == 1) {
        cout << -1;
        return 0;
     }
    }
    cout << 1;
        return 0;
    
    
}