#include <bits/stdc++.h>
using namespace std;
#define finish(x) return cout << x << endl, 0
#define ll long long
const int N = 500001;
int n, k, s[N], sum[N], dep[N], dfstime[N], deg[N], p[N][20];
vector <int> v[N], h[N];
int ct;
void dfsz(int node, int pnode){
dfstime[node] = ct++;
dep[node] = dep[pnode] + 1;
p[node][0] = pnode;
for(int i = 1 ; i < 20 ; i++){
p[node][i] = p[p[node][i - 1]][i - 1];
}
for(auto &i : v[node]){
if(i == pnode) continue;
dfsz(i, node);
}
}
int lift(int node, int k){
for(int i = 19 ; i >= 0 ; i--){
if(k & (1 << i)){
node = p[node][i];
}
}
return node;
}
int LCA(int a, int b){
if(dep[a] > dep[b]) swap(a, b);
b = lift(b, dep[b] - dep[a]);
if(a == b) return a;
for(int i = 19 ; i >= 0 ; i--){
if(p[a][i] != p[b][i]){
a = p[a][i];
b = p[b][i];
}
}
return p[a][0];
}
void add_path(int x, int y){
sum[x]++;
sum[y]++;
sum[LCA(x, y)] -= 2;
}
void dfs(int node, int pnode){
for(auto &i : v[node]){
if(i == pnode) continue;
dfs(i, node);
sum[node] += sum[i];
}
}
void dfs(int node, int pnode, int root){
for(auto &i : v[node]){
if(i == pnode) continue;
if(sum[i] == 0){
deg[root]++;
deg[i]++;
dfs(i, node, i);
}
else dfs(i, node, root);
}
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> k;
for(int i = 0 ; i < n - 1 ; i++){
int x, y;
cin >> x >> y;
v[x].push_back(y);
v[y].push_back(x);
}
for(int i = 1 ; i <= n ; i++){
cin >> s[i];
h[s[i]].push_back(i);
}
dfsz(1, 0);
for(int i = 1 ; i <= k ; i++){
sort(h[i].begin(), h[i].end(), [&](int l, int r){
return dfstime[l] < dfstime[r];
});
int nn = h[i].size();
for(int j = 0 ; j < nn ; j++){
add_path(h[i][j], h[i][(j + 1) % nn]);
}
}
dfs(1, 0);
dfs(1, 0, 1);
int ans = 0;
for(int i = 1 ; i <= n ; i++){
ans += deg[i] == 1;
}
cout << (ans + 1) / 2 << endl;
}
