// Call my Name and Save me from The Dark
#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<int, int> pii;
#define SZ(x) (int) x.size()
#define F first
#define S second
const int N = 5e5 + 10;
int S[N], ps[N], St[N], big[N], C[N], P[N], H[N], M[N], HD[N], A[N], n, k, tim, ret = 0;
vector<int> adj[N], vec[N];
void szDFS(int v, int p = -1) {
S[v] = 1;
for (int u : adj[v]) {
if (u != p) {
H[u] = H[v] + 1, P[u] = v;
szDFS(u, v); S[v] += S[u];
if (S[u] > S[big[v]]) big[v] = u;
}
}
}
void HLD(int v, int p = -1) {
if (p == -1) HD[v] = v;
St[v] = tim++;
if (big[v]) HD[big[v]] = HD[v], HLD(big[v], v);
for (int u : adj[v]) {
if (u != p && u != big[v]) {
HD[u] = u, HLD(u, v);
}
}
}
int LCA(int u, int v){
while (HD[u] != HD[v]){
if (H[HD[u]] > H[HD[v]]) u = P[HD[u]];
else v = P[HD[v]];
}
return H[u] < H[v] ? u : v;
}
void DFS(int v, int p = -1) {
for (int u : adj[v]) {
if (u != p) {
DFS(u, v);
ps[v] += ps[u], C[v] += C[u];
if (!ps[u]) M[u] = 1;
}
}
if (~p && !ps[v] && !C[v]) C[v] = 1;
}
void calcDFS(int v, int p = -1, int cnt = 0) {
int sum = 0, id = 0;
if (M[v] && !cnt) ret++, cnt = 1;
for (int u : adj[v]) {
if (u != p) {
sum += C[u];
if (C[u] >= C[id]) id = u;
}
}
if (sum - C[id] + cnt >= C[id]) ret += max(0, (sum - cnt) / 2) + (max(0, (sum - cnt)) & 1);
else ret += sum - C[id], calcDFS(id, v, cnt + sum - C[id]);
}
int main() {
scanf("%d%d", &n, &k);
for (int i = 1; i < n; i++) {
int u, v; scanf("%d%d", &u, &v);
adj[v].push_back(u);
adj[u].push_back(v);
}
for (int i = 1; i <= n; i++) scanf("%d", &A[i]), vec[A[i]].push_back(i);
szDFS(1); HLD(1);
for (int i = 1; i <= k; i++) {
sort(vec[i].begin(), vec[i].end(), [&] (int u, int v) { return St[u] < St[v]; });
for (int j = 0; j + 1 < SZ(vec[i]); j++) {
int p = LCA(vec[i][j], vec[i][j + 1]);
ps[p] -= 2, ps[vec[i][j + 1]]++, ps[vec[i][j]]++;
}
}
DFS(1);
calcDFS(1);
printf("%d\n", ret);
return 0;
}
