#include <bits/stdc++.h>
using namespace std;
#define task "main"
#define F first
#define S second
#define ii pair<int, int>
#define il pair<int, long long>
#define li pair<long long, int>
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
template <class T1, class T2>
bool maximize(T1 &a, T2 b){
if (a < b) {a = b; return true;}
return false;
}
template <class T1, class T2>
bool minimize(T1 &a, T2 b){
if (a > b) {a = b; return true;}
return false;
}
template <class T>
void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
for(auto item: container) out << item << separator;
out << finish;
}
const int MAX_N = (int)5e5 + 4;
int nNode, nColor;
vector<int> adj[MAX_N];
int color[MAX_N];
int total[MAX_N], cnt[MAX_N];
int sz[MAX_N];
void DFS_size(int u, int p) {
sz[u] = 1;
for (int v : adj[u]) if (v != p) {
DFS_size(v, u);
sz[u] += sz[v];
}
}
int cntFull = 0, ans = INT_MAX;
void update(int u, int p, int val) {
int col = color[u];
cnt[col] += val;
if (cnt[col] == total[col] && val == 1) cntFull++;
else if (cnt[col] == total[col] - 1 && val == -1) cntFull--;
for (int v : adj[u]) if (v != p)
update(v, u, val);
}
void DFS_calc(int u, int p) {
int bigChild = 0;
for (int v : adj[u]) if (v != p)
if (bigChild == 0 || sz[bigChild] < sz[v])
bigChild = v;
for (int v : adj[u]) if (v != p && v != bigChild) {
DFS_calc(v, u);
update(v, u, -1);
}
if (bigChild) DFS_calc(bigChild, u);
for (int v : adj[u]) if (v != p && v != bigChild)
update(v, u, 1);
cnt[color[u]]++;
if (cnt[color[u]] == total[color[u]]) cntFull++;
if (u != 1)
minimize(ans, min(cntFull, nColor - cntFull));
}
void solve() {
cin >> nNode >> nColor;
FOR(i, 2, nNode) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
FOR(i, 1, nNode) cin >> color[i], total[color[i]]++;
DFS_size(1, -1);
DFS_calc(1, -1);
cout << ans;
}
int32_t main() {
if (fopen(task".inp", "r")) {
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
bool multitest = 0;
int numTest = 1;
if (multitest) cin >> numTest;
while (numTest--) {
solve();
}
return 0;
}
/* Lak lu theo dieu nhac!!!! */
