#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;

int main() {
	int N;
	cin >> N;

	vector<int64_t> v(N);
	for (int i = 0; i < N; i++) {
		cin >> v.at(i);
	}

	while (v.size() > 1) {
		for (int i = 0; i < v.size() - 1; i++) {
			v.at(i) += v.at(i + 1);
			v.at(i) %= 1000000007;
		}
		v.pop_back();
	}

	cout << v.at(0) << endl;
}