#include<bits/stdc++.h>
#define ll long long
using namespace std;
inline ll read()
{
	ll x=0,f=1;
	char ch=getchar();
	while(ch<'0'||ch>'9')
	{
		if(ch=='-')f=-1;
		ch=getchar();
	}
	while(ch>='0'&&ch<='9')
	{
		x=(x<<1)+(x<<3)+(ch&15);
		ch=getchar();
	}
	return x*f;
}
inline void write(ll x)
{
	if(x<0)
	{
		putchar('-');
		x=-x;
	}
	if(x>9)write(x/10);
	putchar(x%10+'0');
	return;
}
const ll mod=1000000007;
ll n,c,a[82];
struct Matrix
{
	ll a[82][82];
	Matrix(){memset(a,0,sizeof a);}
	inline Matrix operator*(Matrix b)
	{
		Matrix res;
		for(int i=1;i<=81;++i)
			for(int j=1;j<=81;++j)
				for(int k=1;k<=81;++k)
					res.a[i][j]=(res.a[i][j]+a[i][k]*b.a[k][j]%mod)%mod;
		return res;
	}
}ans,base;
inline void qpow(ll y)
{
	while(y)
	{
		if(y&1)ans=base*ans;
		base=base*base;
		y>>=1;
	}
}
inline ll qpow(ll x,ll y)
{
	ll res=1;
	while(y)
	{
		if(y&1)res=(res*x)%mod;
		x=(x*x)%mod;
		y>>=1;
	}
	return res;
}
int main()
{
	n=read(),c=read();
	for(int i=1;i<=n;++i)a[i]=read(),ans.a[i][1]=1;
	for(int i=1;i<=n;++i)
		for(int j=i;j<=n;++j)
			base.a[j][i]=a[i];
	qpow(c);
	ll res=ans.a[n][1];
	for(int i=1;i<=n;++i)res=(res-qpow(a[i],c)+mod)%mod;
	write(res);
	return 0;
}