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

int main(){
    int N;  cin >> N;
    vector<int> a(N);
    for(int i=0; i<N; i++) cin >> a[i];

    ll mod = 1e9+7;
    ll ans = 0;
    ll c = 1;
    for(int i=0; i<N; i++){
        ans += ((c%mod)*a[i])%mod;
        ans = ans%mod;
        c = (N-1-i)*c/(i+1);
    }
    cout << ans << endl;    
}