#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
const int N = 5e5 + 5, LG = 19;
int n, k;
int dep[N], pr[LG][N], lab[N], top[N], lst[N], deg[N];
vector<int> g[N];
void dfs(int u) {
for (int v : g[u]) {
if (v != pr[0][u]) {
pr[0][v] = u;
for (int j = 1; j < LG; ++j) {
pr[j][v] = pr[j - 1][pr[j - 1][v]];
}
dep[v] = dep[u] + 1;
dfs(v);
}
}
}
int get(int u) {
return lab[u] < 0 ? u : lab[u] = get(lab[u]);
}
void unite(int u, int v) {
u = get(u);
v = get(v);
if (u != v) {
if (lab[u] > lab[v]) {
swap(u, v);
}
lab[u] += lab[v];
lab[v] = u;
if (dep[top[v]] < dep[top[u]]) {
top[u] = top[v];
}
}
}
int lca(int u, int v) {
if (dep[u] < dep[v]) {
swap(u, v);
}
for (int j = LG - 1; ~j; --j) {
if (dep[u] - (1 << j) >= dep[v]) {
u = pr[j][u];
}
}
if (u == v) {
return u;
}
for (int j = LG - 1; ~j; --j) {
if (pr[j][u] ^ pr[j][v]) {
u = pr[j][u], v = pr[j][v];
}
}
return pr[0][u];
}
void up(int u, int x) {
while (dep[top[get(u)]] >= dep[x]) {
unite(u, top[get(u)]);
}
}
void add(int u, int v) {
int x = lca(u, v);
up(u, x);
up(v, x);
}
int main() {
ios::sync_with_stdio(false); cin.tie(nullptr);
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);
}
dep[1] = 1;
dfs(1);
for (int i = 1; i <= n; ++i) {
top[i] = pr[0][i];
lab[i] = -1;
}
for (int i = 1; i <= n; ++i) {
int c; cin >> c;
if (lst[c]) {
add(lst[c], i);
}
lst[c] = i;
}
for (int u = 1; u <= n; ++u) {
for (int v : g[u]) {
if (get(u) != get(v)) {
++deg[get(v)];
}
}
}
int cnt = count(deg + 1, deg + n + 1, 1);
if (cnt & 1) {
cout << cnt / 2 + 1;
exit(0);
}
cout << cnt / 2;
return 0;
}
