#include<iostream>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<algorithm>
#include<utility>

using namespace std;

#define int long long
#define endl "\n"

constexpr long long INF = (long long)1e18;
constexpr long long MOD = 1000000007; 

struct fast_io {
	fast_io(){
		std::cin.tie(nullptr);
		std::ios::sync_with_stdio(false);
	};
} fio;

signed main(){
	cout<<fixed<<setprecision(10);
	
	int N;
	vector<int> A;
	vector<vector<int>> dp;
	
	cin>>N;
	
	A.resize(N);
	dp.resize(N+1, vector<int>(4));
	
	for(int i = 0; i < N; i++){
		cin>>A[i];
	}
	
	dp[1][0] = A[0];
	dp[1][1] = 0;
	dp[1][2] = A[0];
	dp[1][3] = 0;
	
	for(int i = 2; i <= N; i++){
		dp[i][0] = (dp[i-1][0] + dp[i-1][0] + dp[i-1][1] + dp[i-1][1]) % MOD;
		dp[i][1] = (dp[i-1][2] * A[i-1] + dp[i-1][3])%MOD;
		dp[i][2] = (dp[i-1][2] * A[i-1] + 0) % MOD;
		dp[i][3] = (dp[i-1][3] + dp[i][0]) % MOD;
	}
	
	cout<<(dp[N][0]+dp[N][1])%MOD<<endl;
	
	return 0;
}