#include<bits/stdc++.h>
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("trapv")
#define st first
#define nd second
#define pb push_back
#define eb emplace_back
#define pp(x) pop_back(x)
#define mp(a, b) make_pair(a, b)
#define all(x) (x).begin(), (x).end()
#define rev(x) reverse(all(x))
#define sor(x) sort(all(x))
#define sz(x) (int)(x).size()
#define rsz(x) resize(x)
using namespace std;
///~~~~~~~~~~~~~~~~~~~~~~~~~~
template <typename H, typename T>
ostream& operator<<(ostream& os, pair<H, T> m){
return os <<"("<< m.st<<", "<<m.nd<<")";
}
template <typename H>
ostream& operator<<(ostream& os, vector<H> V){
os<<"{";
for(int i=0; i<V.size(); i++){
if(i)os<<" ";
os<<V[i];
}
os<<"}";
return os;
}
void debug(){cerr<<"\n";}
template <typename H, typename... T>
void debug(H h, T... t) {cerr<<h; if (sizeof...(t)) cerr << ", "; debug(t...);}
#define deb(x...) cerr<<#x<<" = ";debug(x);
//#define deb(x...) ;
///~~~~~~~~~~~~~~~~~~~~~~~~~
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<pii > vii;
typedef vector<ll> vl;
typedef vector<pll> vll;
typedef string str;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template <typename T>
using ordered_set =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define BOOST ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const int K=19, N=1<<K, INF=1e9+5, mod2=1e9+7, mod=998244353;
struct modint{
int n=0;
modint(){}
modint(ll x){
n=x%mod;
if(n<0)n+=mod;
}
operator int(){
return n;
}
modint operator+(modint a){a.n = n+a.n; if(a.n>=mod)a.n-=mod;return a;}
modint operator+=(modint a){return (*this)=(*this)+a;}
modint operator-(modint a){a.n = n-a.n; if(a.n<0)a.n+=mod;return a;}
modint operator-=(modint a){return (*this)=(*this)-a;}
modint operator*(modint a){a.n = (n*1ll*a.n)%mod; return a;}
modint operator*=(modint a){return (*this)=(*this)*a;}
modint operator^(const ll &m)const{
modint a(1);
if(m==0)return a;
if(m==1)return (*this);
a=(*this)^(m/2);
a*=a;
return a*((*this)^(m&1));
}
modint odw(){
return (*this)^((ll)mod-2);
}
modint operator/(modint a){return (*this)*a.odw();}
modint operator/=(modint a){return (*this)=(*this)/a;}
bool operator==(modint a){return a.n==n;}
friend ostream& operator<<(ostream& os, modint m) {
return os << m.n;
}
};
modint fact[N], fact2[N];
typedef vector<modint> vm;
void factinit(){
fact[0]=1;
for(int i=1; i<N; i++){
fact[i]=(fact[i-1]*modint(i))%mod;
}
fact2[N-1]=fact[N-1].odw();
for(int i=N-2; i>=0; i--){
fact2[i]=(fact2[i+1]*modint(i+1))%mod;
}
}
modint npok(int _n, int _k){
return fact[_n]*fact2[_k]*fact2[_n-_k];
}
vi E[N], E2[N], kto[N];
int r[N], col[N], par[K][N], d[N];
int find(int v){
if(r[v]==v)return v;
return r[v]=find(r[v]);
}
void Union(int a, int b){
a=find(a);
b=find(b);
r[a]=b;
}
void dfs(int v){
for(int i:E[v]){
if(i!=par[0][v]){
d[i]=d[v]+1;
par[0][i]=v;
dfs(i);
}
}
}
int lca(int u, int v){
if(u==v)return u;
if(d[u]>d[v])swap(u, v);
for(int k=K-1; k>=0; k--){
if(d[u]+(1<<k)<=d[v])v=par[k][v];
}
if(u==v)return v;
for(int k=K-1; k>=0; k--){
if(par[k][u]!=par[k][v]){
u=par[k][u];
v=par[k][v];
}
}
return par[0][v];
}
int main(){
//factinit();
//BOOST;
int n, k;
cin>>n>>k;
for(int i=1; i<n; i++){
int u, v;
cin>>u>>v;
E[u].pb(v);
E[v].pb(u);
}
for(int i=1; i<=n; i++){
int c;
cin>>c;
kto[c].pb(i);
r[i]=i;
}
d[1]=1;
dfs(1);
for(int k=1; k<K; k++){
for(int i=1; i<=n; i++){
par[k][i]=par[k-1][par[k-1][i]];
}
}
for(int i=1; i<=k; i++){
int v=kto[i][0];
for(int j:kto[i]){
v=lca(v, j);
}
for(int j:kto[i]){
while(find(j)!=find(v)){
Union(j, par[0][j]);
j=find(j);
}
}
}
for(int i=2; i<=n; i++){
if(find(i)!=find(par[0][i])){
E2[find(i)].pb(find(par[0][i]));
E2[find(par[0][i])].pb(find(i));
}
}
int l=0;
for(int i=1; i<=n; i++){
if(E2[i].size()){
E2[i].resize(unique(all(E2[i]))-E2[i].begin());
if(E2[i].size()==1)l++;
}
}
cout<<(l+1)/2;
}
