#include <bits/stdc++.h>
using namespace std;
#define int long long
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
const int N = 5e5 + 5;
vector<int> g[N], states[N];
int depth[N];
int DP[20][N];
int par[N];
int Find(int x) {
if(par[x] == x) {
return x;
}
return par[x] = Find(par[x]);
}
void Unite(int a, int b) {
a = Find(a), b = Find(b);
if(depth[a] > depth[b]) {
swap(a, b);
}
par[b] = a;
}
void dfs(int node, int parent) {
DP[0][node] = parent;
for(auto i: g[node]) {
if(i == parent) {
continue;
}
depth[i] = depth[node] + 1;
dfs(i, node);
}
}
int LCA(int x, int y) {
if(depth[x] > depth[y]) {
swap(x, y);
}
int diff = depth[y] - depth[x];
for(int i = 19; i >= 0; i--) {
if((1 << i) <= diff) {
diff -= (1 << i);
y = DP[i][y];
}
}
if(x == y) {
return x;
}
for(int i = 19; i >= 0; i--) {
if(DP[i][x] != DP[i][y]) {
x = DP[i][x];
y = DP[i][y];
}
}
return DP[0][x];
}
bool cmp(int a, int b) {
return depth[a] > depth[b];
}
void Solve() {
for(int i = 0; i < N; i++) {
par[i] = i;
}
int n, k;
cin >> n >> k;
for(int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
depth[1] = 1;
dfs(1, -1);
for(int i = 1; i < 20; i++) {
for(int j = 1; j <= n; j++) {
if(DP[i - 1][j] == -1) {
DP[i][j] = -1;
}
else {
DP[i][j] = DP[i - 1][DP[i - 1][j]];
}
}
}
for(int i = 1; i <= n; i++) {
int cur_state;
cin >> cur_state;
states[cur_state].push_back(i);
}
for(int i = 1; i <= k; i++) {
sort(states[i].begin(), states[i].end(), cmp);
/*cout << "i = " << i << ", size = " << states[i].size() << "\n";
for(int j = 0; j < states[i].size(); j++) {
cout << states[i][j] << " ";
}
cout << "\n";*/
int len = states[i].size();
int node = states[i][0];
for(int j = 1; j < len; j++) {
int lca = LCA(node, states[i][j]);
int cur_node = Find(node);
while(depth[cur_node] > depth[lca]) {
Unite(cur_node, DP[0][cur_node]);
cur_node = Find(cur_node);
}
cur_node = Find(states[i][j]);
while(depth[cur_node] > depth[lca]) {
Unite(cur_node, DP[0][cur_node]);
cur_node = Find(cur_node);
}
node = lca;
}
}
int degree[n + 1];
for(int i = 0; i <= n; i++) {
degree[i] = 0;
}
for(int i = 1; i <= n; i++) {
for(auto j: g[i]) {
if(Find(j) != Find(i) && j != DP[0][i]) {
degree[Find(i)]++;
degree[Find(j)]++;
}
}
}
int ans = 0;
/*for(int i = 1; i <= n; i++) {
cout << degree[i] << " ";
}
cout << "\n";
for(int i = 1; i <= n; i++) {
cout << Find(i) << " ";
}
cout << "\n";*/
for(int i = 1; i <= n; i++) {
if(degree[i] == 1) {
ans++;
}
}
cout << ans / 2 << "\n";
}
int32_t main() {
auto begin = std::chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
//cin >> t;
while(t--) {
Solve();
}
auto end = std::chrono::high_resolution_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
return 0;
}
