#include<bits/stdc++.h>
#define LL long long 
#define Ri register LL 
using namespace std;
const int N=315;
const LL mo=1e9+7;
LL f[N],g[N],K,ans=1,n,c[N],C[N][N],h[N][N];
LL ksm(LL x,LL y){
	LL res=1;
	while(y>0){
		if(y&1) res=res*x%mo;
		x=x*x%mo;
		y>>=1;
	}
	return res;
}
int main(){
	scanf("%lld %lld",&n,&K);
	for(Ri i=1; i<=n; ++i){
		int x;
		scanf("%d",&x),c[x]++;
	}
	for(Ri i=0; i<=n; ++i) C[i][0]=1;
	for(Ri i=1; i<=n; ++i){
		for(Ri j=1; j<=i; ++j) C[i][j]=(C[i-1][j]+C[i-1][j-1])%mo;
	}
	h[0][0]=1;
	for(Ri i=1; i<=n; ++i){
		for(Ri j=1; j<=i; ++j){
			for(Ri k=1; k<=min(i,K); ++k) h[i][j]+=h[i-k][j-1]*k%mo*C[i-1][k-1]%mo;
			h[i][j]%=mo;
		}
		LL o=1;
		for(Ri j=1; j<=i; ++j){
			o=o*i%mo;
			if(j&1) g[i]+=h[i][j]*o%mo;
			else g[i]-=h[i][j]*o%mo;
		}
		g[i]=(g[i]%mo*ksm(i,mo-3))%mo;
	}
	for(Ri i=1; i<=n; ++i) g[i]=g[i]*i%mo*n%mo;
	f[0]=1;
	for(Ri i=1; i<=n; ++i){
		for(Ri j=1; j<=i; ++j) f[i]+=f[i-j]*g[j]%mo*C[i-1][j-1]%mo;
		f[i]%=mo;
	}
//	for(Ri i=1; i<=n; ++i) printf("%lld ",f[i]);
	for(Ri i=1; i<=n; ++i) ans*=f[c[i]]%mo;
	printf("%lld\n",(ans*ksm(n,mo-3)%mo+mo)%mo);
	return 0;
}