#include <iostream>
#include <algorithm>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    int n;
    cin >> n;
    vector<int> v(n);
    for (auto &&j : v) scanf("%d", &j);
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < n-i-1; ++j) {
            v[j] = (v[j]+v[j+1])%MOD;
        }
    }
    cout << v[0] << "\n";
    return 0;
}