#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using ld = long double;

int main() {
  int N;
  cin >> N;
  vector<ll> a(N + 1);
  for (int i = 1; i <= N; i++) cin >> a[i];
  for (int i = 1; i <= N - 1; i++) {
    for (int j = 1; j <= (N - 1) - i + 1; j++) {
      a[j] = (a[j] + a[j + 1]) % 1000000007;
    }
  }
  cout << a[1] << endl;
  return 0;
}