#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define bitcount __builtin_popcountll
#define all(a) (a).begin(), (a).end()
using namespace std;
using namespace __gnu_pbds;
template<typename T> using ordered_set = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 5e5 + 1;
vector<pair<int,int>> adj[N];
unordered_map<int,int> stl[N];
bool sep[N];
int tot[N], region[N], deg[N];
void dfs1(int u, int p = -1) {
if (tot[stl[u].begin()->first] == 1)
stl[u].clear();
for (auto [v, ind] : adj[u]) {
if (v == p) continue;
dfs1(v, u);
if (stl[v].empty()) {
sep[ind] = true;
// cout << u << " " << v << "\n";
}
if (stl[u].size() < stl[v].size())
swap(stl[u], stl[v]);
for (auto [col, frq] : stl[v]) {
auto [it, succ] = stl[u].emplace(col, 0);
it->second += frq;
if (it->second == tot[col]) {
stl[u].erase(it);
}
}
}
}
int timer = 0;
void dfs2(int u, int p = -1) {
region[u] = timer;
for (auto [v, ind] : adj[u]) {
if (v == p) continue;
timer += sep[ind];
dfs2(v, u);
}
}
signed main() {
ios::sync_with_stdio(false);
cin.tie(nullptr), cout.tie(nullptr);
int n, k; cin >> n >> k;
for (int i = 0, u, v; i < n-1; i++) {
cin >> u >> v;
adj[u].emplace_back(v, i);
adj[v].emplace_back(u, i);
}
for (int i = 1, col; i <= n; i++) {
cin >> col;
tot[col]++;
stl[i][col]++;
}
dfs1(1);
dfs2(1);
for (int u = 1; u <= n; u++) {
for (auto [v, ind] : adj[u]) {
if (sep[ind]) {
deg[region[u]]++;
deg[region[v]]++;
}
}
}
int ans = 0;
for (int i = 1; i <= n; i++)
ans += deg[i] == 2;
cout << (ans + 1)/2;
}
