#include <bits/stdc++.h>
template <long long mod>
class Combination
{
    std::vector<long long> fact, finv, inv;
public:
    Combination() {}
    Combination(int sz)
    {
        fact.resize(sz);
        finv.resize(sz);
        inv.resize(sz);
        fact[0] = 1;
        for (int i = 1; i < sz; ++i)
        {
            fact[i] = fact[i - 1] * i % mod;
        }
        inv[0] = 0;
        inv[1] = 1;
        for (int i = 2; i < sz; ++i)
        {
            inv[i] = mod - inv[mod % i] * (mod / i) % mod;
        }
        finv[0] = 1;
        for (int i = 1; i < sz; ++i)
        {
            finv[i] = finv[i - 1] * inv[i] % mod;
        }
    }
    long long C(long long n, long long k)
    {
        if (n < k)
            return 0;
        if (n < 0 || k < 0)
            return 0;
        return (fact[n] * finv[k] % mod) * finv[n - k] % mod;
    }
    long long P(long long n, long long k)
    {
        if (n < k)
            return 0;
        if (n < 0 || k < 0)
            return 0;
        return fact[n] * finv[n - k] % mod;
    }
    long long H(long long n, long long k)
    {
        return this->C(n + k - 1, k);
    }
    long long getfact(int i)
    {
        return fact[i];
    }
    long long getinv(int i)
    {
        return inv[i];
    }
    long long getfinv(int i)
    {
        return finv[i];
    }
};
using namespace std;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vll = vector<ll>;
using vvll = vector<vll>;
using P = pair<int, int>;
const double eps = 1e-8;
const ll MOD = 1000000007;
const int INF = INT_MAX / 2;
const ll LINF = LLONG_MAX / 2;
template <typename T1, typename T2>
bool chmax(T1 &a, const T2 &b) {
  if(a < b) {a = b; return true;}
  return false;
}
template <typename T1, typename T2>
bool chmin(T1 &a, const T2 &b) {
  if(a > b) {a = b; return true;}
  return false;
}
template<typename T1, typename T2>
ostream& operator<<(ostream &os, const pair<T1, T2> p) {
  os << p.first << ":" << p.second;
  return os;
}
template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  for(int i=0;i<((int)(v.size()));++i) {
    if(i) os << " ";
    os << v[i];
  }
  return os;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  int n; cin >> n;
  vll a(n);
  for(int i=0;i<(n);++i) cin >> a[i];
  Combination<MOD> comb(1000);
  ll su = 0;
  for(int i=0;i<(n);++i) {
    su += a[i] * comb.C(n-1, i);
    su %= MOD;
  }
  cout << su << endl;
}