#include <iostream>
#include <vector>
#include <climits>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <bitset>
#include <utility>
#include <numeric>
#include <queue>
#include <stack>

using ll = long long;
using namespace std;

constexpr int MOD = 1e9 + 7;
constexpr ll MOD_LL = ll(1e9 + 7);

int main(void) {
	int n;
	cin >> n;
	
	vector<ll> a(n);
	for(int i = 0; i < n; ++i) {
		cin >> a[i];
	}
	
	vector< vector<ll> > b(n, vector<ll>(n, 0));
	for(int i = 0; i < n; ++i) {
		b[0][i] = a[i];
	}
	
	for(int i = 1; i < n; ++i) {
		for(int j = 0; j < n - 1; ++j) {
			b[i][j] = (b[i - 1][j] + b[i - 1][j + 1]) % MOD_LL;
		}
	}
	
	cout << b[n - 1][0] << endl;
	
	return 0;
}