// In the name of God
//-MILY-
#include<bits/stdc++.h>
using namespace std;
#define pb push_back
#define fi first
#define se second
#define mp make_pair
typedef long long ll;
const int N = 5e5 + 5;
int n, k;
vector<int> adj[N], vec[N];
int mn[N], tin[N], tout[N], T;
int ans, h[N], cnt, c[N];
bool vis[N], mark[N];
void dfs(int v, int p) {
tin[v] = ++T;
for (auto u : adj[v]) {
if (u == p)
continue;
dfs(u, v);
}
tout[v] = ++T;
}
void dfs2(int v, int p) {
vis[v] = true;
mn[v] = h[v];
bool tmp = false;
for (auto u : adj[v]) {
if (!vis[u]) {
h[u] = h[v] + 1;
dfs2(u, v);
if (mn[u] > h[v]) {
mark[u] = true;
cnt++;
}
mn[v] = min(mn[v], mn[u]);
}
else if (u != p || tmp) {
mn[v] = min(mn[v], h[u]);
}
if (u == p)
tmp = true;
}
}
void dfs3(int v) {
vis[v] = true;
for (auto u : adj[v]) {
if (!vis[u]) {
dfs3(u);
c[v] += c[u];
if (mark[u])
c[v]++;
}
}
ans += mark[v] && (c[v] == 0 || c[v] == cnt - 1);
}
void solve() {
cin >> n >> k;
for (int i = 0; i < n - 1; i++) {
int v, u; cin >> v >> u;
adj[v].pb(u), adj[u].pb(v);
}
for (int i = 1; i <= n; i++) {
int s; cin >> s;
vec[s].pb(i);
}
dfs(1, 0);
for (int i = 1; i <= k; i++) {
vector<pair<int, int> > V;
for (auto v : vec[i]) {
V.pb(mp(tin[v], v));
}
sort(V.begin(), V.end());
for (int i = 0; i < (int)V.size(); i++) {
int j = (i + 1) % (int)V.size();
adj[V[i].se].pb(V[j].se);
adj[V[j].se].pb(V[i].se);
}
}
dfs2(1, 0);
memset(vis, 0, sizeof vis);
dfs3(1);
cout << (ans + 1) / 2 << '\n';
}
int32_t main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
