#include<bits/stdc++.h>
using namespace std;
#define FOR(i,l,r) for(long long i=(l);i<(r);++i)
#define REP(i,n) FOR(i,0,n)

int d[4] = {1, 1, 2, 6};
const int MOD = 1e9 + 7;

int main(){
    int n; 
    cin >> n;
    vector<int> a(n);
    REP(i, n) cin >> a[i];
    REP(i, n) if(!a[i]){
        cout << -1 << endl;
        return 0;
    }
    long long mul = 1;
    REP(i, n){
        if(a[i] >= 4){
            cout << MOD << endl;
            return 0;
        }
        mul *= pow(a[i], d[a[i]]);
        if(mul > MOD){
            cout << MOD << endl;
            return 0;
        }
    }
    cout << MOD % mul << endl;
}