//0 1 1 0 1
//0 1 0 0 1
//1 0 0 1 1
//0 1 1 0 1
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
#define F first
#define S second
#define pb push_back
#define sze size()
#define all(x) x.begin() , x.end()
#define wall__ cout << "--------------------------------------\n";
#define kids int mid = (tl + tr) >> 1, cl = v << 1, cr = v << 1 | 1
#define file_io freopen("input.cpp", "r", stdin); freopen("output.cpp", "w", stdout);
typedef long long ll;
typedef long double dl;
typedef pair < int , int > pii;
typedef pair < int , ll > pil;
typedef pair < ll , int > pli;
typedef pair < ll , ll > pll;
typedef pair < int , pii > piii;
typedef pair < ll, pll > plll;
const ll N = 1e5 + 10;
const ll mod = 1e9 + 7;
const ll inf = 2e16;
const ll INF = 1e9 + 10;
const ll lg = 32;
int n, k, a[N], timer, c[N], sub[N], cnt, lst = 0;
vector < int > g[N];
vector < pii > edg[N];
vector < int > mark[N];
int we[N];
void dfs (int v, int p) {
sub[v] = 1; mark[v][a[v]] = 1;
for (auto u : g[v]) {
if (u == p) continue;
dfs(u, v);
sub[v] += sub[u];
for (int i = 1; i <= k; i++) mark[v][i] |= mark[u][i];
}
ll x = 0;
for (int y = 1; y <= k; y++) {
if (mark[v][y]) x += c[y];
}
int w = 0;
if (x == sub[v]) {
w = 1;
}
we[lst] = w;
if (v != 1) {
edg[v].pb({p, lst});
edg[p].pb({v, lst});
}
++lst;
cnt += w;
}
int h[N];
pii par[N];
void dfs0(int v, int p) {
for (auto e : edg[v]) {
int u = e.F;
if (u == p) continue;
h[u] = h[v] + we[e.S];
dfs0(u, v);
}
}
void dfs1(int v, int p, int id) {
par[v] = {p, id};
h[v] = h[p] + we[id];
for (auto e : edg[v]) {
int u = e.F;
if (u == p) continue;
dfs1(u, v, e.S);
}
}
void solve () {
cin >> n >> k;
for (int i = 1; i < n; i++) {
int v, u; cin >> v >> u;
g[v].pb(u); g[u].pb(v);
}
for (int i = 1; i <= n; i++) {
mark[i].resize(k + 1, 0);
}
for (int i = 1; i <= n; i++) {
cin >> a[i]; ++c[a[i]];
}
dfs(1, 0);
int ans = 0;
--cnt;
while(cnt) {
fill(h, h + (n + 1), 0);
dfs0(1, 0);
int mx = 0;
for (int i = 1; i <= n; i++) if (h[mx] < h[i]) mx = i;
++ans;
fill(h, h + (n + 1), 0);
fill(par, par + (n + 1), make_pair(0, 0));
dfs1(mx, 0, 0);
int mx2 = 0;
for (int i = 1; i <= n; i++) if (h[mx2] < h[i]) mx2 = i;
while(mx2 != mx) {
int id = par[mx2].S;
cnt -= we[id];
we[id] = 0;
mx2 = par[mx2].F;
}
}
cout << ans << '\n';
}
int main() {
// ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {solve();}
return 0;
}
/*
*/
//shrek will AC this;
