/* -*- coding: utf-8 -*-
 *
 * 797.cc:  No.797 Noelちゃんとピラミッド - yukicoder
 */

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<vector>
#include<map>
#include<set>
#include<stack>
#include<list>
#include<queue>
#include<deque>
#include<algorithm>
#include<numeric>
#include<utility>
#include<complex>
#include<functional>
 
using namespace std;

/* constant */

const int MAX_N = 100000;
const int MOD = 1000000007;

/* typedef */

typedef long long ll;

/* global variables */

ll cs[MAX_N];

/* subroutines */

ll powmod(ll a, int n) {  // a^n % MOD
  ll pm = 1;
  while (n > 0) {
    if (n & 1) pm = (pm * a) % MOD;
    a = (a * a) % MOD;
    n >>= 1;
  }
  return pm;
}

/* main */

int main() {
  int n;
  scanf("%d", &n);
  int m = n - 1;

  cs[0] = cs[m] = 1;
  for (int i = 1; i * 2 <= m; i++)
    cs[i] = cs[m - i] =
      cs[i - 1] * (m + 1 - i) % MOD * powmod(i, MOD - 2) % MOD;

  ll sum = 0;
  for (int i = 0; i < n; i++) {
    ll ai;
    scanf("%lld", &ai);
    sum = (sum + ai * cs[i] % MOD) % MOD;
  }

  printf("%lld\n", sum);
  return 0;
}