#include<bits/stdc++.h>
#include<bits/extc++.h>
#define int long long
#define inf 0x3f3f3f3f3f3f3f3f
#define maxn 1234567
#define eps 1e-7
#define mod 1000000007
#define Mod 998244353
#define f(i,a,b) for(int i=a;i<=b;i++)
#define r(i,a,b) for(int i=a;i>=b;i--) 
#define fx(i,a,b,x) for(int i=a;i<=b;i+=x)
#define rx(i,a,b,x) for(int i=a;i>=b;i-=x) 
using namespace std;
using namespace __gnu_cxx;
using namespace __gnu_pbds;
int T;
int n,b,s[maxn],p[maxn],ans,g,mx;
int qpow(int a,int n,int m){
	int ans=1;
	while(n){
		if(n&1)ans=ans*a%m;
		a=a*a%m;
		n>>=1;
	}
	return ans;
}
int Min(int a,int b){
	return a<b?a:b;
}
int Max(int a,int b){
	return a>b?a:b;
}
void solve(){
	scanf("%lld%lld",&n,&b);
	f(i,1,n)scanf("%lld",&s[i]),p[i]=i;
	do{
		g=1,mx=s[p[1]];
		f(i,2,n){
			if(mx<s[p[i]])g++;
			mx=Max(mx,s[p[i]]);
		}
		ans=(ans+g*qpow(b,g,mod)%mod)%mod;
	}while(next_permutation(p+1,p+n+1));
	printf("%lld\n",ans);
}
signed main(){
	T=1;
//	scanf("%lld",&t);
	while(T--)solve();
	return 0;
}