#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    ll n;
    cin >> n;
    ll MOD = 1e9+7;
    ll a[n];
    rep(i,n)cin >> a[i];
    drep(i,n){
        rep(j,i){
            a[j] = a[j] + a[j+1];
            a[j] %= MOD;
        }
    }
    cout << a[0] << endl;
    return 0;
}