// Template
#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <queue>
#include <deque>
#include <stack>
#include <tuple>
#include <map>
#include <set>
#include <algorithm>
#include <utility>
#include <cmath>
#include <complex>
#define rep(i, x) for (int i = 0; i < (x); ++i)
#define rng(i, x, y) for (int i = (x); i < (y); ++i)
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
using namespace std;
using ll = long long;
constexpr int inf = 1001001001;
constexpr ll INF = 3003003003003003003;
template <typename T> inline bool chmin(T &x, const T &y) {if (x > y) {x = y; return 1;} return 0;}
template <typename T> inline bool chmax(T &x, const T &y) {if (x < y) {x = y; return 1;} return 0;}
void solve();
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(10);
    solve();
    return 0;
}

// Mod-Int
constexpr int MOD = 1000000007;
struct ModInt {
    ll val;
    ModInt() = default;
    ModInt(ll x) : val(x % MOD + (x < 0 ? MOD : 0)) {}
    ModInt &operator+= (const ModInt &x) {if ((val += x.val) >= MOD) val -= MOD; return *this;}
    ModInt &operator-= (const ModInt &x) {if ((val -= x.val) < 0) val += MOD; return *this;}
    ModInt &operator*= (const ModInt &x) {(val *= x.val) %= MOD; return *this;}
    ModInt operator+ (const ModInt &x) const {return ModInt(*this) += x;}
    ModInt operator- (const ModInt &x) const {return ModInt(*this) -= x;}
    ModInt operator* (const ModInt &x) const {return ModInt(*this) *= x;}
    ModInt pow(ll t) const {
        if (!t) return ModInt(1);
        ModInt m = pow(t / 2);
        m *= m;
        if (t & 1) m *= *this;
        return m;
    }
    ModInt inv() const {return pow(MOD - 2);}
    ModInt &operator/= (const ModInt &x) {return *this *= x.inv();}
    ModInt operator/ (const ModInt &x) const {return ModInt(*this) /= x;}
    friend istream &operator>> (istream &is, ModInt &x) {is >> x.val; return is;}
    friend ostream &operator<< (ostream &os, const ModInt &x) {os << x.val; return os;}
};

// Main Code
void solve() {
    int n;
    cin >> n;
    vector<ModInt> a(n);
    rep(i, n) cin >> a[i];
    
    rep(i, n - 1) {
        vector<ModInt> b = a;
        rep(j, n - i - 1) b[j] = a[j] + a[j + 1];
        swap(a, b);
    }
    
    cout << a[0] << "\n";
    return;
}