#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef pair<int, int> pii;
#define all(x) (x).begin(),(x).end()
#define X first
#define Y second
#define sep ' '
#define endl '\n'
#define SZ(x) ll(x.size())
const ll MAXN = 5e5 + 10;
const ll LOG = 22;
const ll INF = 8e18;
const ll MOD = 1e9 + 7; //998244353; //1e9 + 9;
int n , k , timer , ans , col[MAXN] , par[LOG][MAXN] , H[MAXN] , st[MAXN] , ps[MAXN] ,mark[MAXN];
vector<int> adj[MAXN] , vec[MAXN];
int cmp(int x , int y){
return st[x] < st[y];
}
void PreDFS(int v , int p = 0){
par[0][v] = p;
st[v] = timer++;
H[v] = H[p] + 1;
for(int u : adj[v]){
if(u == p) continue;
PreDFS(u , v);
}
}
int getPar(int v , int h){
for(int i = 0 ; i < LOG ; i++){
if(h & (1 << i)){
v = par[i][v];
}
}
return v;
}
int LCA(int v , int u){
if(H[v] > H[u]) swap(v , u);
u = getPar(u , H[u] - H[v]);
if(v == u) return v;
for(int i = LOG - 1 ; i >= 0 ; i--){
if(par[i][v] != par[i][u]){
v = par[i][v];
u = par[i][u];
}
}
return par[0][v];
}
void SolveDFS(int v , int p = -1){
for(int u : adj[v]){
if(u == p) continue;
SolveDFS(u , v);
ps[v] += ps[u];
if(ps[u] == 0 && mark[u] == 0) ans++;
if(ps[u] == 0) mark[v] = 1;
mark[v] |= mark[u];
}
}
int main() {
ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
cin >> n >> k;
for(int i = 1 ; i < n ; i++){
int v , u;
cin >> v >> u;
adj[v].push_back(u);
adj[u].push_back(v);
}
for(int i = 1 ; i <= n ; i++){
cin >> col[i];
vec[col[i]].push_back(i);
}
PreDFS(1);
for(int i = 1 ; i < LOG ; i++){
for(int j = 0 ; j <= n ; j++){
par[i][j] = par[i - 1][par[i - 1][j]];
}
}
for(int i = 1 ; i <= k ; i++){
sort(all(vec[i]) , cmp);
for(int j = 0 ; j + 1 < SZ(vec[i]) ; j++){
int v = vec[i][j] , u = vec[i][j + 1];
int lca = LCA(v , u);
ps[v]++; ps[u]++; ps[lca] -= 2;
}
}
SolveDFS(1);
cout << (ans + 1) / 2 << endl;
return 0;
}
/*
*/
