#include<bits/stdc++.h>
using namespace std;

/*******  All Required define Pre-Processors and typedef Constants *******/
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define rep(i,n) for(int i=0; i<(n); ++i)
#define rep1(i,n) for(int i=1; i<=(n); ++i)
#define Dcout(a) cout << setprecision(20) << a << endl
#define MP make_pair
#define PB push_back
#define EPS 1e-9
#define PI 3.1415926535897932384626433832795
#define MOD 1000000007
using ll = long long;
using PAIR = pair<int, int>;
using Graph = vector<vector<int>>;
//const ll INF = (1LL << 60);
//const double pi=acos(-1.0);
#define debug cout << "line : " << __LINE__ << " debug" << endl
/****** Template of some basic operations *****/
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
/**************************************/

/******** User-defined Function *******/

/**************************************/

/********** Main()  function **********/
int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  int n; cin >> n;
  vector<ll> a(n);
  rep(i,n) cin >> a[i];

  int d = n-1;
  for(int i=n-1; i>0; --i){
    for(int j=0; j<i; ++j){
      a[j] = (a[j] + a[j+1]) % MOD ;
    }
  }

  cout << a[0] << endl;

  return 0;
}
/********  Main() Ends Here *************/