#include <iostream>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <string>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <tuple>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cassert>
#include <cstdint>
#include <cctype>
#include <numeric>
#include <bitset>
#include <functional>

using namespace std;

using ll =  long long;
using Pll = pair<ll, ll>;
using Pii = pair<int, int>;

constexpr int INF = 1 << 30;
constexpr ll LINF = 1LL << 60;
constexpr ll MOD = 1000000007;
constexpr long double EPS = 1e-10;
constexpr int dyx[4][2] = {
    { 0, 1}, {-1, 0}, {0,-1}, {1, 0}
};
constexpr int N_MAX = 100;

ll fact[N_MAX+1], rfact[N_MAX+1];

ll perm(ll n, ll k) {
    if(n-k < 0LL) return 0LL;
    return (fact[n] * rfact[n-k]) % MOD;
}

ll comb(ll n, ll k) {
    if(n-k < 0LL) return 0LL;
    return (perm(n, k) * rfact[k]) % MOD;
}

ll modpow(ll a, ll p) {
    ll ret = 1LL;
    while(p) {
        if(p & 1) {
            ret = (ret * a) % MOD;
        }
        a = (a * a) % MOD;
        p >>= 1;
    }
    return ret;
}

void init_fact(ll n) {
    fact[0] = fact[1] = 1;
    rfact[0] = rfact[1] = 1;
    for(ll i=2;i<=n;++i) {
        fact[i] = (fact[i-1] * i) % MOD;
        rfact[i] = modpow(fact[i], MOD-2);
    }
}


int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    int n;
    cin >> n;
    init_fact(n+1);
    vector<ll> a(n);
    ll ans = 0LL;
    for(int i=0;i<n;++i) {
        cin >> a[i];
        ans += (a[i] * comb(n-1, i)) % MOD;
        ans %= MOD;
    }
    cout << ans << endl;
}