#include <bits/stdc++.h>
#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 = 5e5 + 69;
const int K = 52;
int n, k;
int a[N], cnt[N], up[N], is_leaf[N];
vii g[N], c[K], t[N];
int have[N][K];
void dfs(int v, int p) {
have[v][a[v]] = 1;
for (auto u : g[v]) {
if (u == p) continue;
dfs(u, v);
for (int j = 1; j <= k; j++) {
have[v][j] += have[u][j];
}
}
int ok = 1;
for (int j = 1; j <= k; j++) {
if (have[v][j] > 0)
ok &= (have[v][j] == (int)c[j].size());
}
cnt[v] = ok;
}
void build(int v, int p, int c_node) {
int x = c_node;
if (cnt[v] && v > 1) {
t[v].push_back(c_node);
t[c_node].push_back(v);
up[v] = c_node;
x = v;
}
for (auto u : g[v]) {
if (u == p) continue;
build(u, v, x);
}
}
void calc(int v, int p) {
if (t[v].size() == 1 && v > 1)
is_leaf[v] = 1;
for (auto u : t[v]) {
if (u == p) continue;
calc(u, v);
is_leaf[v] += is_leaf[u];
}
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> n >> k;
// Clear previous test case data
for (int i = 1; i <= n; i++) {
g[i].clear();
t[i].clear();
cnt[i] = is_leaf[i] = up[i] = 0;
for (int j = 1; j <= k; j++) {
have[i][j] = 0;
}
}
for (int j = 1; j <= k; j++) {
c[j].clear();
}
// Read tree edges
for (int i = 1; i <= n - 1; i++) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
// Read state assignments
for (int i = 1; i <= n; i++) {
cin >> a[i];
c[a[i]].push_back(i);
}
dfs(1, 0);
build(1, 0, 1);
calc(1, 0);
assert(cnt[1] == 1);
int o = 0;
for (int i = 1; i <= n; i++) {
if (cnt[i] && t[i].size() == 1)
o += 1;
}
int ans = (o + 1) / 2;
cout << ans << '\n';
return 0;
}
