#include <iostream>
#include <vector>
#include <climits>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <bitset>
#include <utility>
#include <numeric>
#include <queue>
#include <stack>

using ll = long long;
using namespace std;

constexpr int MOD = 1e9 + 7;
constexpr ll MOD_LL = ll(1e9) + 7;

int main(void) {
	int n;
	cin >> n;
	
	vector<ll> a(n);
	for(int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	
	vector< vector<int> > nCk(n, vector<int>(n));
	nCk[0][0] = 1;
	for(int i = 1; i < n; ++i) {
		nCk[i][0] = 1;
		
		for(int j = 1; j < n; ++j) {
			nCk[i][j] = nCk[i - 1][j - 1] + nCk[i - 1][j];
		}
	}
	
	ll ans = 0LL;
	for(int i = 0; i < n; ++i) {
		ans += (a[i] * (ll)nCk[n - 1][i]) % MOD_LL;
		ans %= MOD_LL;
		
	}
	
	cout << ans << endl;
	
	return 0;
}