#include <bits/stdc++.h>
#define int long long
#define double long double
#define arr2 array<int, 2>
#define popcount __builtin_popcountll
#define ctz __builtin_ctzll
#define arr3 array<int, 3>
using namespace std;
const int N = 5e5 + 10, M = 1e9 + 7;
vector<int> adj[N];
int n, k;
int col[N];
int cnt[N];
int ths[N];
int par[N];
int sz[N];
int cnt1[N];
vector<arr2> cut;
stack<vector<int>> stk;
void crt(int a) {
par[a] = a;
sz[a] = 1;
}
int get(int a) {
return (a == par[a] ? a : (par[a] = get(par[a])));
}
void mrg(int a, int b) {
a = get(a), b = get(b);
if (a == b) {
return;
}
if (sz[a] > sz[b]) {
swap(a, b);
}
par[a] = b;
sz[b] = sz[a] + sz[b];
}
bool same(int a, int b) {
return get(a) == get(b);
}
void dfs(int a, int b = 0) {
stk.push(vector<int>(k + 1));
for (int i = 0; i <= k; ++i) {
stk.top()[i] = ths[i];
}
ths[col[a]]++;
for (int i : adj[a]) {
if (i != b) {
dfs(i, a);
}
}
if (a == 1) {
return;
}
for (int i = 0; i <= k; ++i) {
if ((ths[i] - stk.top()[i] != 0) and (ths[i] - stk.top()[i] != cnt[i])) {
mrg(a, b);
stk.pop();
return;
}
}
cut.push_back({a, b});
stk.pop();
}
void fun() {
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) {
int a;
cin >> a;
col[i] = a;
cnt[a]++;
crt(i);
}
dfs(1);
for (arr2 i : cut) {
cnt1[get(i[0])]++, cnt1[get(i[1])]++;
}
int c = 0;
for (int i = 1; i <= n; ++i) {
if (cnt1[i] == 1) {
c++;
}
}
cout << (c + 1) / 2 << "\n";
}
int32_t main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
// int tc;
// cin >> tc;
// while (tc--)
fun();
}
