#include <bits/stdc++.h>

using namespace std;

#define REP(i,n) for(int i=0; i<(int)(n); i++)
#define FOR(i,b,e) for (int i=(int)(b); i<(int)(e); i++)
#define ALL(x) (x).begin(), (x).end()

const double PI = acos(-1);

long long MOD = 1e9 + 7;
long long comb[128][128];

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

  for (int i = 0; i < 128; i++) {
    comb[i][0] = comb[i][i] = 1;
    for (int j = 1; j < i; j++)
      comb[i][j] = (comb[i-1][j] + comb[i-1][j-1]) % MOD;
  }

  long long ret = 0;
  int n;
  cin >> n;
  REP (i, n) {
    long long a;
    cin >> a;
    ret += a * comb[n-1][i] % MOD;
    ret %= MOD;
  }
  cout << ret << endl;
  
  return 0;
}