#include <bits/stdc++.h>
using namespace std;
template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl
using ll = long long;
const int maxn = 5e5 + 10;
int n, k;
vector<int> g[maxn];
int a[maxn];
const int LOG = 20;
int dep[maxn];
int par[LOG+1][maxn];
void dfs(int at, int p) {
for (int j=1; j<LOG; j++) {
par[j][at] = par[j-1][par[j-1][at]];
}
for (int to: g[at]) {
if (to == p) continue;
par[0][to] = at;
dep[to] = 1+dep[at];
dfs(to, at);
}
}
int lca(int u, int v) {
if (dep[u]>dep[v]) {
swap(u,v);
}
// u
// v
int dx = dep[v]-dep[u];
for (int j=LOG-1; j>=0; j--) {
if (dx>>j&1) {
v = par[j][v];
}
}
if (u==v) return u;
for (int j=LOG-1; j>=0; j--) {
if (par[j][u] != par[j][v]) {
u = par[j][u];
v = par[j][v];
}
}
return par[0][v];
}
vector<int> nodes[maxn];
int dp[maxn];
void dfs2(int at, int p) {
for (int to: g[at]) {
if (to == p) continue;
dfs2(to, at);
dp[at] += dp[to];
}
}
int deg[maxn];
int P[maxn];
void dfs3(int at, int p) {
if (dp[at]==0) {
if (p!=-1) {
// add edge
// p-->at
if (at != p) {
deg[at]++;
deg[P[p]]++;
}
P[at] = at;
}
} else {
P[at] = P[p];
}
for (int to: g[at]) {
if (to == p) continue;
dfs3(to, at);
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin>>n>>k;
for (int i=0; i<n-1; i++) {
int u,v; cin>>u>>v;
--u; --v;
g[u].push_back(v);
g[v].push_back(u);
}
for (int i=0; i<n; i++) {
cin>>a[i];
--a[i];
nodes[a[i]].push_back(i);
}
dfs(0, -1);
for (int i=0; i<n; i++) {
dp[i] = 1;
}
for (int j=0; j<k; j++) {
int mid = nodes[j][0];
for (int x: nodes[j]) {
mid = lca(mid, x);
}
dp[mid] -= nodes[j].size();
}
dfs2(0, -1);
// for (int i=0; i<n; i++) {
// cout<<i<<": "<<dp[i]<<endl;
// }
dfs3(0, -1);
int leaves = 0;
for (int i=0; i<n; i++) {
if (deg[i]==1) leaves++;
}
cout<<(leaves+1)/2<<endl;
return 0;
}
