#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define x first
#define y second
ll N, K, A[500005], S[500005], vis[500005];
vector<ll> T[500005];
ll Size(ll u, ll p){
S[u] = 1;
for(auto v : T[u]){
if(v != p && !vis[v]) S[u] += Size(v, u);
}
return S[u];
}
ll Cent(ll u, ll p, ll n){
for(auto v : T[u]){
if(v != p && !vis[v] && S[v] > n / 2) return Cent(v, u, n);
}
return u;
}
ll Cnt[500005];
vector<ll> G[500005], H[500005];
void dfs(ll u, ll p, ll d){
Cnt[A[u]] += d;
for(auto v : T[u]){
if(v == p || vis[v]) continue;
dfs(v, u, d);
}
}
ll Comp(ll u, ll p, ll c){
ll ok = (Cnt[A[u]] > 0);
for(auto v : T[u]){
if(v == p || vis[v]) continue;
if(Comp(v, u, c)) ok = 1;
}
if(ok){
G[c].push_back(A[u]); G[A[u]].push_back(c);
}
return ok;
}
void dnc(ll _u){
ll u = Cent(_u, -1, Size(_u, -1));
vis[u] = 1;
Cnt[A[u]]++;
for(auto v : T[u]){
if(!vis[v]) dfs(v, u, 1);
}
for(auto v : T[u]){
if(vis[v]) continue;
dfs(v, u, -1);
Comp(v, u, A[u]);
dfs(v, u, 1);
}
for(auto v : T[u]){
if(!vis[v]) dfs(v, u, -1);
}
Cnt[A[u]]--;
for(auto v : T[u]){
if(!vis[v]) dnc(v);
}
}
ll deg[500005], Num[500005];
void f(ll u){
for(auto v : G[u]){
if(Num[v]) continue;
Num[v] = Num[u]; f(v);
}
}
ll chk[500005];
int main(){
cin.tie(0) -> sync_with_stdio(0);
cin >> N >> K;
for(ll i = 1; i < N; i++){
ll u, v; cin >> u >> v;
T[u].push_back(v); T[v].push_back(u);
}
for(ll i = 1; i <= N; i++){
cin >> A[i];
}
dnc(1);
for(ll i = 1; i <= N; i++){
for(auto j : G[i]){
if(chk[j]) continue;
H[i].push_back(j);
chk[j] = 1;
}
for(auto j : H[i]) chk[j] = 0;
}
for(ll i = 1, j = 0; i <= N; i++){
if(Num[i]) continue;
Num[i] = ++j; f(i);
}
for(ll i = 1; i <= N; i++){
for(auto j : T[i]){
if(i > j) continue;
ll a = Num[A[i]], b = Num[A[j]];
if(a != b){
deg[a]++, deg[b]++;
}
}
}
ll f = 0;
for(ll i = 1; i <= N; i++){
if(deg[i] == 1) f++;
}
cout << (f + 1) / 2;
}
