#include <bits/stdc++.h>

using namespace std;
constexpr int MOD = 1000000007;
int main(){

    int n;
    cin >> n;
    vector<long long> a(n);
    for(int i = 0; i < n; ++i){
        cin >> a[i];
        a[i] %= MOD;
    }
    for(int i = 0; i < n; ++i){
        for(int j = 0; j < n-i-1; ++j){
            a[j] += a[j+1];
            a[j] %= MOD;
        }
    }
    cout << a[0] << '\n';

    return 0;
}