//Challenge: Accepted
#include <bits/stdc++.h>
using namespace std;
#ifdef zisk
void debug(){cout << endl;}
template<class T, class ... U> void debug(T a, U ... b){cout << a << " ", debug(b...);}
template<class T> void pary(T l, T r) {
while (l != r) cout << *l << " ", l++;
cout << endl;
}
#else
#define debug(...) 0
#define pary(...) 0
#endif
#define ll long long
#define maxn 200005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
vector<int> adj[maxn], pos[maxn];
int c[maxn], siz[maxn];
int pa[maxn];
bool vis[maxn], col[maxn], mark[maxn], done[maxn], ins[maxn];
void dfs(int n, int par, vector<int> &vec) {
vec.push_back(n);
pa[n] = par;
siz[n] = 1;
for (int v:adj[n]) {
if (v != par && !mark[v]) {
dfs(v, n, vec);
siz[n] += siz[v];
}
}
}
int getcent(int n, int par, int tot) {
for (int v:adj[n]) {
if (v != par && !mark[v] && siz[v] * 2 >= tot) return getcent(v, n, tot);
}
return n;
}
int ans = 1<<30;
void solve(vector<int> a) {
if (a.size() == 0) return;
pary(a.begin(), a.end());
vector<int> tmp;
dfs(a[0], 0, tmp);
int root = getcent(a[0], 0, siz[a[0]]);
dfs(root, 0, tmp);
if (!done[c[root]]) {
for (int i:a) col[c[i]] = 0, vis[i] = 0, ins[i] = 1;
bool check = 1;
queue<int> que;
vis[root] = 1;
col[c[root]] = 1;
int cnt = 0;
for (int v:pos[c[root]]) {
if (!ins[v]) {
check = 0;
break;
}
que.push(v);
}
while (que.size()) {
if (!check) break;
int cur = que.front();que.pop();
while (!vis[cur]) {
vis[cur] = 1;
if (!col[c[cur]]) {
cnt++;
col[c[cur]] = 1;
for (int v:pos[c[cur]]) {
if (!ins[v]) {
check = 0;
break;
}
que.push(v);
}
}
cur = pa[cur];
}
}
if (check) ans = min(ans, cnt);
done[c[root]] = 1;
for (int i:a) ins[i] = 0;
}
mark[root] = 1;
for (int v:adj[root]) {
if (mark[v]) continue;
vector<int> rec;
dfs(v, root, rec);
solve(rec);
}
}
int main() {
io
int n, K;
cin >> n >> K;
for (int i = 0;i < n - 1;i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
vector<int> ini;
for (int i = 1;i <= n;i++) {
cin >> c[i];
pos[c[i]].push_back(i);
ini.push_back(i);
}
solve(ini);
cout << ans << endl;
}
