#include <iostream>
#include <vector>
#include <algorithm>
#include <queue>
#include <string>
#include <functional>
#include <set>
#include <map>
#define DB cerr<<"D"<<endl
#define pb push_back
using namespace std; using ll=long long; using ld=long double; const int INF=1e9; const ll LINF=1e18; const double dINF = 1e18; const ld ldINF = 1e18; const double EPS = 1e-6;
template<typename T, typename U, typename O> void caut(T a, U b, O c){cout<<"("<<a<<","<<b<<","<<c<<") ";} template<typename T, typename U> void caut(T a, U b){cout<<"("<<a<<","<<b<<") ";} template<typename T> void caut(T a){cout<<"("<<a<<") ";}
using P=pair<int,int>;
const ll M = 1e9+7, mx = 200000;
void add(ll& x, ll y) {x+=y; x%=M;}; void mul(ll& x, ll y) {x*=y; x%=M;}; void chmax(ll& x, ll y) {if (x<y) x=y;}; void chmin(ll& x, ll y) {if (x>y) x=y;};

int main() {
  int n;cin>>n;
  ll a[n]; for(int i=0;i<n;i++) cin>>a[i];
  for(int i=0;i<n;i++) {
    ll b[n];
    for(int j=0;j<n-1;j++) {
      b[j]=(a[j]+a[j+1])%M;
    }
    copy(b,b+n-1-i,a);
  }
  a[0]%=M;
  cout<<a[0]<<endl;
}