#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll MOD = 1000000007;
const long long INF = 1LL << 60;
#define rep(i,n) for(int i = 0; i < n; i++)
#define all(x) (x).begin(),(x).end()

int main() {
    ll n, ans;
    cin >> n >> ans;
    rep(i,n-1){
        ll a;
        cin >> a;
        ans *= a+1;
        ans %= MOD;
    }
    cout << ans << endl;
}