#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < n; ++i)
typedef long long ll;
using namespace std;

const int MOD = 1e9 + 7;

int main() {
    int N;
    cin >> N;
    vector<int> A(N);
    rep(i, N) cin >> A[i];

    for (int i = N - 1; i >= 0; --i) {
        rep(j, i) {
            A[j] += A[j + 1];
            A[j] %= MOD;
        }
    }

    cout << A[0] << endl;

    return 0;
}