#include <bits/stdc++.h>
using namespace std;

typedef long long int ll;
ll MOD = 1000000007;
ll INFL = 1ll << 60;
ll INF = 1 << 30;

int main() {
  int n;
  cin >> n;
  vector<ll> ncr(n);
  ncr[0] = 1;
  for (int i = 0; i < n - 1; i++) {
    ncr[i + 1] = ncr[i] * (n - 1 - i) / (i + 1);
  }

  ll a, ans = 0;
  for (int i = 0; i < n; i++) {
    cin >> a;
    ans = (ans + (a * ncr[i] % MOD)) % MOD;
  }
  cout << ans << endl;
}