#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 p[500005];
ll Find(ll n) { return (p[n] < 0 ? n : p[n] = Find(p[n])); }
void Union(ll u, ll v) { u = Find(u), v = Find(v); if(u != v) p[u] += p[v], p[v] = u; }
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 chk[500005];
void dfs(ll u, ll p, ll c){
chk[u] = (A[u] == c);
for(auto v : T[u]){
if(v == p || vis[v]) continue;
dfs(v, u, c);
if(chk[v]) chk[u] = 1;
}
if(chk[u]){
if(Find(A[u]) != Find(c)){
Union(A[u], c);
}
}
}
void dnc(ll _u){
ll u = Cent(_u, -1, Size(_u, -1));
vis[u] = 1;
for(auto v : T[u]){
if(vis[v]) continue;
dfs(v, u, A[u]);
}
for(auto v : T[u]){
if(vis[v]) continue;
dnc(v);
}
}
ll deg[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];
}
fill(p, p + N + 1, -1LL);
dnc(1);
for(ll i = 1; i <= N; i++){
for(auto j : T[i]){
if(i > j) continue;
ll a = Find(A[i]), b = Find(A[j]);
if(a != b){
deg[a]++, deg[b]++;
}
}
}
ll Cnt = 0;
for(ll i = 1; i <= N; i++){
if(deg[i] == 1) Cnt++;
}
cout << (Cnt + 1) / 2;
}
