#include<bits/stdc++.h>
using namespace std;
namespace my_std{
	#define ll long long
	#define bl bool
	ll my_pow(ll a,ll b,ll mod){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res=(res*a)%mod;
			a=(a*a)%mod;
			b>>=1;
		}
		return res;
	}
	ll qpow(ll a,ll b){
		ll res=1;
		if(!b) return 1;
		while(b){
			if(b&1) res*=a;
			a*=a;
			b>>=1;
		}
		return res;
	}
	#define db double
	#define pf printf
	#define pc putchar
	#define fr(i,x,y) for(register ll i=(x);i<=(y);i++)
	#define pfr(i,x,y) for(register ll i=(x);i>=(y);i--)
	#define go(u) for(ll i=head[u];i;i=e[i].nxt)
	#define enter pc('\n')
	#define space pc(' ')
	#define fir first
	#define sec second
	#define MP make_pair
	#define il inline
	#define inf 8e18
	#define random(x) rand()*rand()%(x)
	#define inv(a,mod) my_pow((a),(mod-2),(mod))
	il ll read(){
		ll sum=0,f=1;
		char ch=0;
		while(!isdigit(ch)){
			if(ch=='-') f=-1;
			ch=getchar();
		}
		while(isdigit(ch)){
			sum=sum*10+(ch^48);
			ch=getchar();
		}
		return sum*f;
	}
	il void write(ll x){
		if(x<0){
			x=-x;
			pc('-');
		}
		if(x>9) write(x/10);
		pc(x%10+'0');
	}
	il void writeln(ll x){
		write(x);
		enter;
	}
	il void writesp(ll x){
		write(x);
		space;
	}
}
using namespace my_std;
#define mod 1000000007
ll n,lim,cnt[330],jc[330],jcinv[330],pw[330][330];
ll f[330][330],F[330],g[330][330],h[330][330],ans=0;
il ll C(ll nn,ll mm){
	return jc[nn]*jcinv[mm]%mod*jcinv[nn-mm]%mod;
}
int main(){
	n=read();
	lim=read();
	fr(i,1,n){
		ll x=read();
		cnt[x]++;
	}
	jc[0]=1;
	fr(i,1,n) jc[i]=jc[i-1]*i%mod;
	jcinv[n]=inv(jc[n],mod);
	pfr(i,n-1,0) jcinv[i]=jcinv[i+1]*(i+1)%mod;
	fr(i,1,n){
		pw[i][1]=jcinv[i]*jc[i-1]%mod;
		fr(j,2,n) pw[i][j]=pw[i][j-1]*i%mod;
	}
	f[0][0]=1;
	fr(i,1,n) fr(j,1,i) fr(k,1,min(i,lim)) f[i][j]=(f[i][j]+f[i-k][j-1]*C(i-1,i-k)%mod*pw[k][k]%mod*k)%mod;
	fr(i,1,n){
		fr(j,1,i){
			if((j-1)&1) F[i]=(F[i]-f[i][j]*pw[i][j]%mod+mod)%mod;
			else F[i]=(F[i]+f[i][j]*pw[i][j])%mod;
		}
	}
	g[0][0]=1;
	fr(i,1,n) fr(j,1,i) fr(k,1,i) g[i][j]=(g[i][j]+g[i-k][j-1]*C(i-1,i-k)%mod*F[k]%mod*k)%mod;
	h[0][0]=1;
	fr(i,1,n) fr(j,0,n) fr(k,0,n-j) h[i][j+k]=(h[i][j+k]+h[i-1][j]*g[cnt[i]][k])%mod;
	fr(i,1,n) ans=(ans+h[n][i]*pw[n][i])%mod;
	write(ans);
}