//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#define ll long long
#define maxn 500005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;
vector<int> adj[maxn], tree[maxn];
int col[maxn], cnt[maxn], siz[maxn], par[maxn], ind[maxn];
bool poss[maxn];
int cur;
void dfs(int n, int pa) {
siz[n] = col[n] == cur ? 1 : 0;
par[n] = pa;
for (int v:adj[n]) {
if (v != pa) {
dfs(v, n);
siz[n] += siz[v];
}
}
if (siz[n] > 0 && siz[n] < cnt[cur]) poss[n] = true;
}
int find(int a) {
return a == ind[a] ? a : ind[a] = find(ind[a]);
}
void Union(int a, int b) {
ind[find(a)] = find(b);
}
int ans = 0;
void dfs2(int n, int par) {
int chi = 0;
for (int v:tree[n]) {
if (v != par) {
dfs2(v, n);
chi++;
}
}
if (chi == 0 || (n == 1 && chi == 1)) ans++;
}
int main() {
io
int n, k;
cin >> n >> k;
for (int i = 0;i < n - 1;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 >> col[i];
cnt[col[i]]++;
ind[i] = i;
}
for (int i = 1;i <= k;i++) {
for (int j = 1;j <= n;j++) siz[j] = 0;
cur = i;
dfs(1, 0);
}
for (int i = 1;i <= n;i++) {
if (poss[i]) Union(i, par[i]);
}
int done = 1;
for (int i = 1;i <= n;i++) {
if (par[i] != 0 && !poss[i]) {
done = 0;
int a = find(i), b = find(par[i]);
tree[a].push_back(b);
tree[b].push_back(a);
}
}
if (done) cout << 0 << "\n";
else {
dfs2(find(1), 0);
cout << (ans + 1) / 2 << "\n";
}
}
/*
5 4
1 2
2 3
3 4
3 5
1
2
1
3
4
5 4
1 2
2 3
3 4
4 5
1
2
3
4
1
2 2
1 2
1
2
*/
