#include <bits/stdc++.h>
#define pii pair <int, int>
#define fi first
#define se second
using namespace std;
const int maxN = 5e5 + 5;
int S[maxN], par[maxN];
vector <int> adj[maxN], all[maxN];
int cnt[maxN];
int up[maxN], depth[maxN];
inline void init (int n) {
for (int i = 1; i <= n; i ++) {
par[i] = i;
}
}
int getRoot (int u) {
if (par[u] == u) {
return u;
}
return (par[u] = getRoot (par[u]));
}
inline void join (int u, int v) {
u = getRoot (u);
v = getRoot (v);
if (u == v) {
return;
}
if (depth[u] > depth[v]) {
swap (u, v);
}
par[v] = u;
return;
}
inline void merge (int u, int v) {
while (u != v) {
//cout << u << ' ' << v << '\n';
if (depth[u] > depth[v]) {
swap (u, v);
}
join (v, up[v]);
v = up[v];
}
}
void dfs (int u, int p) {
up[u] = p;
for (auto v : adj[u]) {
if (v == p) {
continue;
}
depth[v] = depth[u] + 1;
dfs (v, u);
}
}
int main () {
ios_base :: sync_with_stdio (0);
cin.tie (0);
int n, k;
cin >> n >> k;
init (n);
for (int i = 1; i < n; i ++) {
int u, v;
cin >> u >> v;
adj[u].push_back (v);
adj[v].push_back (u);
}
for (int i = 1; i <= n; i ++) {
cin >> S[i];
all[S[i]].push_back (i);
}
dfs (1, 0);
for (int i = 1; i <= k; i ++) {
if (all[i].size () <= 1) {
continue;
}
for (int j = 0; j + 1 < (int) all[i].size (); j ++) {
merge (all[i][j], all[i][j + 1]);
}
}
for (int u = 1; u <= n; u ++) {
for (auto v : adj[u]) {
int i = getRoot (u);
int j = getRoot (v);
if (i != j) {
cnt[i] ++;
}
}
}
int res = 0;
for (int i = 1; i <= n; i ++) {
res += (cnt[i] == 1);
}
cout << (res + 1) / 2;
return 0;
}
