//#pragma GCC optimize("O3")
#include <bits/stdc++.h>
//#include <ctime>
using namespace std;
#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1, (n))
#define pb push_back
#define f first
#define s second
typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<piii> viii;
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const int MAXN = 500100, MAXK = 20;
const ll MOD = 1e9+7;
const ll INF = 1e16;
const ld PI = asin(1) * 2;
void setIO () {
FAST_IO;
}
void setIO (string s) {
setIO();
freopen((s+".in").c_str(),"r",stdin);
freopen((s+".out").c_str(),"w",stdout);
}
int n, k;
vi adj[MAXN];
int s[MAXN];
vi bel[MAXN];
int deg[MAXN];
int par[MAXN];
int find (int a) {return par[a] = par[a]==a ? a : find(par[a]);}
bool same (int a, int b) {return find(a) == find(b);}
void unite (int a, int b) {
a = find(a), b = find(b);
if (a == b) return;
par[b] = a;
}
int curT = 0;
vi times[MAXN];
int pr[MAXN][MAXK];
int dep[MAXN];
void dfs1 (int v, int p) {
times[v].pb(++curT);
FOR(i, 1,MAXK-1)
pr[v][i] = pr[pr[v][i-1]][i-1];
for (int u : adj[v]) {
if (u == p) continue;
pr[u][0] = v;
dep[u] = dep[v]+1;
dfs1 (u, v);
times[v].pb(++curT);
}
}
int lca (int v, int u) {
if (u == v) return u;
if (dep[u] > dep[v]) swap(u,v);
int d = dep[v] - dep[u];
FOR(i, 0, MAXK-1)
if (d & (1<<i))
v = pr[v][i];
if (u == v) return u;
for (int i = MAXK-1; i >= 0; i--) {
if (pr[v][i] != pr[u][i]) {
v = pr[v][i];
u = pr[u][i];
}
}
return pr[v][0];
}
int cnt[MAXN];
void dfs3 (int v, int p) {
for (int u : adj[v]) {
if (u == p) continue;
dfs3(u,v);
cnt[v] += cnt[u];
}
// cout << " v = " << v << " cnt = " << cnt[v] << endl;
if (p != -1 && cnt[v] > 0) unite(v,p);
}
void dfs2 (int v, int p) {
for (int u : adj[v]) {
if (u == p) continue;
dfs2(u, v);
}
if (p == -1) return;
if (!same(v,p)) {
deg[find(v)]++;
deg[find(p)]++;
}
}
vii seq;
int main() {
setIO();
// ifstream cin ("in.txt");
cin >> n >> k;
REP(n-1) {
int a, b; cin >> a >> b;
adj[a].pb(b);
adj[b].pb(a);
}
FOR(i, 1, n) cin >> s[i];
FOR(i,1 , n) bel[s[i]].pb(i);
FOR(i, 1, n) par[i] = i;
dfs1 (1, -1);
FOR(i, 1, k) {
seq.clear();
for (int v : bel[i])
for (int t : times[v])
seq.pb({t, v});
sort(seq.begin(), seq.end());
FOR(j, 0, (int)seq.size()-2) {
int u = seq[j].s;
int v = seq[j+1].s;
cnt[u]++;
cnt[v]++;
cnt[lca(u,v)] -= 2;
}
}
dfs3 (1, -1);
dfs2 (1, -1);
//FOR(i, 1, n) cout <<" i = " << i << " deg = " << deg[i] << endl;
//FOR(i, 1, n) cout << " i = " << i << " par = " << par[i] << endl;
int leaves = 0;
FOR(i, 1, n) if (deg[i] == 1) leaves++;
int ans = (leaves+1)/2;
cout << ans <<"\n";
return 0;
}
