#include <algorithm>
#include <array>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <numeric>
#include <optional>
#include <queue>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

int main() {
    int32_t n;
    cin >> n;
    vector<int64_t> as(n);
    for (auto &&a : as) {
        cin >> a;
    }
    const auto MOD = int64_t(1e9) + 7;
    for (; n > 1; --n) {
        for (auto i = 0; i < n - 1; ++i) {
            as[i] = (as[i] + as[i + 1]) % MOD;
        }
    }
    cout << as[0] << endl;
    return 0;
}