#include <iostream>

#include <sstream>

#include <algorithm>

#include <cstdio>

#include <math.h>

#include <set>

#include <map>

#include <queue>

#include <string>

#include <string.h>

#include <bitset>

#define REP(i,a,n) for(int i=a;i<=n;++i)

#define PER(i,a,n) for(int i=n;i>=a;--i)

#define hr putchar(10)

#define pb push_back

#define lc (o<<1)

#define rc (lc|1)

#define mid ((l+r)>>1)

#define ls lc,l,mid

#define rs rc,mid+1,r

#define x first

#define y second

#define io std::ios::sync_with_stdio(false)

#define endl '\n'

#define DB(a) ({REP(__i,1,n) cout<<a[__i]<<' ';hr;})

using namespace std;

typedef long long ll;

typedef pair<int,int> pii;

const int P = 1e9+7, INF = 0x3f3f3f3f;

ll gcd(ll a,ll b) {return b?gcd(b,a%b):a;}

ll qpow(ll a,ll n) {ll r=1%P;for (a%=P;n;a=a*a%P,n>>=1)if(n&1)r=r*a%P;return r;}

ll inv(ll x){return x<=1?1:inv(P%x)*(P-P/x)%P;}

inline int rd() {int x=0;char p=getchar();while(p<'0'||p>'9')p=getchar();while(p>='0'&&p<='9')x=x*10+p-'0',p=getchar();return x;}

//head

#ifdef ONLINE_JUDGE

const int N = 1e6+10;

#else

const int N = 111;

#endif

int n, k, mx, sum;

int a[N], dp[N], vis[N];

vector<int> g[N];

void dfs(int x, int fa, int S) {

	if ((a[x]|S)!=S||vis[x]) return;

	++sum, vis[x]=1;

	for (int y:g[x]) if (y!=fa) dfs(y,x,S);

}

int main() {

	scanf("%d%d", &n, &k);

	REP(i,1,n) a[i]=1<<rd()-1;

	REP(i,2,n) {

		int u=rd(),v=rd();

		g[u].pb(v),g[v].pb(u);

	}

	int mx = (1<<k)-1;

	REP(S,1,mx) {

		REP(i,1,n) vis[i]=0;

		REP(i,1,n) if (!vis[i]) {

			sum = 0, dfs(i,0,S);

			dp[S] = ((ll)sum*(sum-1)%P*(P+1)/2+sum+dp[S])%P;

		}

	}

	int ans = 0;

	REP(S,1,mx) {

		int cnt = 0;

		for (int j=(S-1)&S; j; j=(j-1)&S) dp[S]-=dp[j];

		ans = ((ll)ans+qpow(131,__builtin_popcount(S))*dp[S])%P;

	}

	if (ans<0) ans+=P;

	printf("%d\n", ans);

}