#include <bits/stdc++.h>
using namespace std;
vector<vector<int>> adj, parent;
vector<int> depth;
void dfs(int node, int prev, int dis) {
depth[node] = dis;
parent[node][0] = prev;
for(auto child: adj[node]) if (child != prev) dfs(child, node, dis+1);
}
int ancestor(int x, int k) {
int cnt = 0;
while(k && x) {
if (k&1) x = parent[x][cnt];
k = k>>1; cnt++;
}
return x;
}
int lca(int a, int b) {
if (depth[a] < depth[b]) swap(a, b);
a = ancestor(a, depth[a]-depth[b]);
if (a==b) return a;
for(int k=19; k>=0; k--) {
int aa = parent[a][k];
int bb = parent[b][k];
if (aa != bb) {
a = aa; b = bb;
}
}
return parent[a][0];
}
signed main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n, k; cin >> n >> k;
adj = vector<vector<int>>(n+1);
parent = vector<vector<int>>(n+1, vector<int>(20, 0));
depth = vector<int>(n+1, 0);
for(int i=0; i<n-1; i++) {
int u, v; cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
dfs(1, 0, 0);
for(int k=1; k<20; k++) {
for(int i=1; i<=n; i++) {
if (parent[i][k-1]) parent[i][k] = parent[parent[i][k-1]][k-1];
}
}
vector<int> states(n+1);
vector<bool> stateVisited(k+1, false), nodeVisited(n+1, false);
vector<vector<int>> st(k+1);
for(int i=1; i<=n; i++) {
cin >> states[i];
st[states[i]].push_back(i);
}
int ans = 0;
for(int i=1; i<=k; i++) {
if (stateVisited[i]) continue;
stateVisited[i] = true;
vector<int> queue;
for(auto node: st[i]) {
if (nodeVisited[node]) continue;
nodeVisited[node] = true;
queue.push_back(node);
}
int anc = 0, idx = 0;
while(idx < queue.size()) {
int queueSize = queue.size();
for(int j=idx; j<queueSize; j++) {
int node = queue[j];
if (anc == 0) anc = node;
else anc = lca(anc, node);
}
while(idx < queueSize) {
int node = queue[idx++];
while(node != anc) {
if (!stateVisited[states[node]]) {
stateVisited[states[node]] = true;
for(auto child: st[states[node]]) {
if (nodeVisited[child]) continue;
nodeVisited[child] = true;
queue.push_back(child);
}
}
node = parent[node][0];
}
}
if (!stateVisited[states[anc]]) {
stateVisited[states[anc]] = true;
for(auto child: st[states[anc]]) {
if (nodeVisited[child]) continue;
nodeVisited[child] = true;
queue.push_back(child);
}
}
}
for(auto node: queue) {
if (adj[node].size() == 1) {
ans++;
break;
}
}
}
ans /= 2;
cout << ans << '\n';
return 0;
}
