#include <bits/stdc++.h>
//#include "bigint.h"
#define db(x) cerr << #x << ": " << x << endl
#define print cerr << "Ah shit, here we go again" << endl
#define int long long int
#define vii vector<int>
#define pii pair<int, int>
#define vpi vector<pii>
#define ff first
#define ss second
using namespace std;
const int N = 1e5 + 10;
const int INF = 1e9 + 10;
int n, k;
int a[N], c[N], sub[N], ans, b[N], root, cnt[N];
vii g[N];
vector<int> mark[N];
void dfs(int v, int p) {
sub[v] = 1;
mark[v][a[v]] = 1;
for (auto u : g[v]) {
if (u == p) continue;
dfs(u, v);
sub[v] += sub[u];
cnt[v] += cnt[u];
for (int i = 1; i <= k; i++) {
mark[v][i] |= mark[u][i];
}
}
int x = 0;
for (int y = 1; y <= k; y++) {
if (mark[v][y]) x += c[y];
}
if ((x == sub[v] && v != root)) {
b[v] = 1;
++cnt[v];
}
}
void dfs1(int v, int p) {
if (b[v] == 1) {
if (cnt[v] == 1 || cnt[v] == cnt[root]) ++ans;
}
for (auto u : g[v]) {
if (u == p) continue;
dfs1(u, v);
}
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> n >> k;
for (int i = 1; i < n; i++) {
int v, u; cin >> v >> u;
g[v].push_back(u);
g[u].push_back(v);
}
for (int i = 1; i <= n; i++) {
mark[i].resize(k + 1, 0);
}
for (int i = 1; i <= n; i++) {
cin >> a[i];
++c[a[i]];
}
root = 1;
for (int i = 2; i <= n; i++) {
if (g[i].size() > g[root].size()) root = i;
}
dfs(root, 0);
dfs1(root, 0);
cout << (ans + 1) / 2 << '\n';
return 0;
}
