#include <iostream>
#include <algorithm>
#include <string>
#include <vector>
#include <cmath>
#include <map>
#include <queue>
#include <iomanip>
#include <set>
#include <tuple>
#define mkp make_pair
#define mkt make_tuple
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define all(v) v.begin(),v.end()
using namespace std;
typedef long long ll;
const ll MOD=1e9+7;
template<class T> void chmin(T &a,const T &b){if(a>b) a=b;}
template<class T> void chmax(T &a,const T &b){if(a<b) a=b;}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int N;
  cin>>N;
  vector<ll> A(N);
  rep(i,N) cin>>A[i];

  rep(i,N){
    if(A[i]==0){
      cout<<-1<<endl;
      return 0;
    }
  }

  ll ans=1;
  rep(i,N){
    if(A[i]==1) continue;

    ll num=1;
    for(int k=1;k<=A[i];k++){
      num*=k;
      if(num>=30) break;
    }
    for(int j=1;j<=num;j++){
      ans*=A[i];
      if(ans>MOD){
        cout<<MOD<<endl;
        return 0;
      }
    }
  }
  cout<<MOD%ans<<endl;

  return 0;
}