#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=1444999999;
ll mod=1000000007;
vector<ll>dfs(vector<ll>&a){
    vector<ll>b;
    for (ll i = 1; i < a.size(); i++)
    {
        b.push_back((a[i]+a[i-1])%mod);
    }
    return b;
}
int main(){
    ll n;
    cin >> n;
    vector<ll>a(n);
    for (ll i = 0; i < n; i++)
    {
        cin >> a[i];
    }
    while (a.size()>1)
    {
        a=dfs(a);
    }
    cout << a[0] << endl;
}