/*****************************************
备注：
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#include <queue>
#include <math.h>
#include <stack>
#include <stdio.h>
#include <iostream>
#include <vector>
#include <iomanip>
#include <string.h>
#include <algorithm>
using namespace std;
#define LL long long
const int N = 20;
const int INF = 0x3f3f3f3f;
const int Mod = 1e7 + 7;
struct node
{
	LL a[N][N];
	node()
	{
		memset(a,0,sizeof(a));
		for(int i = 0 ; i < N ; i++)
			a[i][0] = 10 ;
		for(int i = 1 ; i < N ; i++)
			for(int j = 1 ;j <= i ; j++)
				a[i][j] = 1;

	}
};
int n , m;
node operator * (node a , node b)
{
	node c;
	memset(c.a,0 , sizeof(c.a));
	for(int i = 0 ; i <= n+1 ; i++)
		for(int j = 0 ; j <= n+1 ; j++)
		{
			LL sum = 0;
			for(int k = 0 ; k <= n+1 ; k++)
				sum = (sum + a.a[i][k] * b.a[k][j]) %Mod;
			c.a[i][j] = sum;
		}
	return c;
} 
void print(node p)
{
	for(int i = 0 ; i <= n + 1 ; i++)
	{
		for(int j = 0 ; j <= n + 1; j ++)
			cout << p.a[i][j] << " ";
		cout << endl;
	}
}
int main()
{
	while(cin >> n >> m)
	{
		node p;
		for(int i = 0 ; i <= n ; i++)
			p.a[n+1][i] = 0 , p.a[i][n+1] = 3;
		p.a[n+1][n+1] = 1;
		/***************************/
		LL x[100];
		memset(x,0,sizeof(x));
		x[0] = 233;
		for(int i = 1; i <= n ;i++)
		{
			cin >> x[i];
			x[i] = (x[i-1] + x[i])%Mod;
		}
		x[n+1] = 1LL;
		m--;
		node ans;
		memset(ans.a , 0 , sizeof ans.a);
		for(int i = 0 ; i <= n+1 ; i++)
			ans.a[i][i] = 1;
		while(m)
		{
			if(m&1)
				ans = ans * p;
			m >>= 1LL;
			p = p * p;
		}
		// print(ans);
		LL sum = 0;
		
		for(int i = 0 ; i <= n+1 ; i++ )
		{
			sum = (sum + (x[i] * ans.a[n][i])%Mod) %Mod;
		} 
		cout << sum << endl;
	}

	return 0;
}