#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <cmath>
#include <numeric>
#include <utility>
#include <iomanip>

using namespace std;
using int64 = long long;

struct aaa{aaa(){cin.tie(nullptr); ios::sync_with_stdio(false); cout<<fixed<<setprecision(20);};}aaa;

int main() {
    int n;
    cin >> n;
    int mod = 1000000007;
    vector<int> a(n);
    for (int i=0; i<n; i++) cin >> a[i];
    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] << endl;
}