#include "bits/stdc++.h"
#define int long long
using namespace std;
const int MAXN = 5e5 + 10;
vector<int> adj[MAXN];
vector<int> adj2[MAXN];
int s[MAXN];
int dsu[MAXN];
int set_of(int u) {
if(dsu[u] == u) return u;
return dsu[u] = set_of(dsu[u]);
}
void union_(int u, int v) {
dsu[set_of(u)] = set_of(v);
}
int dfs(int node, int prev, int q) {
//stat: do the ancestors contain color q
int cnt = (s[node] == q);
for(int x: adj[node]) {
if(x != prev) {
int d = dfs(x, node, q);
cnt += d;
if(d > 0 && set_of(node) != set_of(x)) {
union_(node, x);
}
}
}
//ret: how many color q in subtree
return cnt;
}
int32_t main() {
int n,k;cin >> n >> k;
for(int i=1;i<n;i++) {
int a,b;cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for(int i=1; i<=n; i++) cin >> s[i];
for(int i=0; i<=n; i++) dsu[i] = i;
for(int i=1; i<=k; i++) {
for(int j=1; j<=n; j++) {
if(s[j] == i) {
dfs(j, -1, i);
break;
}
}
}
map<pair<int, int>, bool> mp;
for(int i=1; i<=n; i++) {
for(int x: adj[i]) {
if(set_of(i) != set_of(x) && mp[{set_of(i), set_of(x)}] == 0) {
mp[{set_of(i), set_of(x)}] = 1;
mp[{set_of(x), set_of(i)}] = 1;
adj2[set_of(i)].push_back(set_of(x));
adj2[set_of(x)].push_back(set_of(i));
}
}
}
int s = 0;
for(int i=1; i<=n; i++) {
s += (adj2[i].size() == 1);
}
cout << (s + 1) / 2 << "\n";
}
/*
6 5
1 2
2 3
2 4
3 5
2 6
1 5 2 4 2 3
myAnswer 3
correctAnswer 2
*/
