#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<vector>
#include<string.h>
#include<math.h>
#include<map>
#include<iomanip>
#include<queue>

const long long INF = 1e6+7;
const long long MOD = 1e9+7;
const double PI=acos(-1);

using namespace std;

int main(){
	int n;
	cin >> n;
	vector<vector<long long>> a(20000);
	for(int i=0;i<n;i++){
		long long temp;
		cin >> temp;
		a[0].push_back(temp);
	}
	
	int id=1;
	while(1){
		for(int i=0;i<a[id-1].size()-1;i++){
			a[id].push_back((a[id-1][i]+a[id-1][i+1])%MOD);
		}
		if(a[id].size()<=1){
			break;
		}
		id++;
	}
	cout << a[id][0] << endl;
	return 0;
}