#include <bits/stdc++.h>
#define int long long
using namespace std;
vector<vector<int>> adj;
vector<int> etat;
vector<vector<int>> dansEtat;
vector<int> profondeur;
vector<int> parent;
vector<int> id;
int nbSommets, nbEtats;
void dfs(int u, int p)
{
for (auto v : adj[u])
if (v != p)
{
profondeur[v] = profondeur[u] + 1;
parent[v] = u;
dfs(v, u);
}
}
int find(int u)
{
return id[u] = (u == id[u] ? u : find(id[u]));
}
signed main(void)
{
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> nbSommets >> nbEtats;
vector<pair<int, int>> aretes;
id.resize(nbSommets);
for (int i(0); i < nbSommets; ++i)
id[i] = i;
adj.resize(nbSommets);
etat.resize(nbSommets);
dansEtat.resize(nbEtats);
parent.resize(nbSommets);
profondeur.resize(nbSommets);
for (int i(1); i < nbSommets; ++i)
{
int u, v;
cin >> u >> v;
--u, --v;
aretes.emplace_back(u, v);
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i(0); i < nbSommets; ++i)
{
cin >> etat[i];
--etat[i];
dansEtat[etat[i]].push_back(i);
}
dfs(0, 0);
for (int iEtat(0); iEtat < nbEtats; ++iEtat)
{
for (int i(1); i < (int)dansEtat[iEtat].size(); ++i)
{
int u = dansEtat[iEtat][i-1], v = dansEtat[iEtat][i];
u = find(u), v = find(v);
while (u != v)
{
if (profondeur[u] < profondeur[v]) swap(u, v);
id[u] = find(id[parent[u]]);
u = id[u];
}
}
}
vector<int> deg(nbSommets);
for (auto [u, v] : aretes)
{
u = find(u), v = find(v);
if (u != v)
deg[u]++, deg[v]++;
}
int nbFeuilles(0);
for (auto d : deg)
nbFeuilles += d == 1;
int sol = (nbFeuilles + 1)/2;
cout << sol << endl;
}
