// vaziat meshki-ghermeze !
#include <bits/stdc++.h>
#define pb push_back
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define debug(x) cerr << #x << " : " << x << '\n'
using namespace std;
typedef long long ll;
typedef long double ld;
typedef string str;
typedef pair<ll, ll> pll;
const ll Mod = 1000000007LL;
const int N = 5e5 + 10;
const ll Inf = 2242545357980376863LL;
const ll Log = 30;
int dep[N], par[N], anc[N];
vector<int> G[N];
void DFS(int u, int p, int d){
dep[u] = d;
anc[u] = p;
for(auto adj : G[u])
if(adj != p)
DFS(adj, u, d + 1);
}
int Find(int u){
if(par[u] == u) return u;
return par[u] = Find(par[u]);
}
void Unite(int u, int v){
u = Find(u);
v = Find(v);
par[u] = v;
}
void Merge(int u, int v){
// cerr << "!! " << u << ' ' << v << '\n';
while((u = Find(u)) != (v = Find(v))){
if(dep[u] < dep[v]) swap(u, v);
Unite(u, anc[u]);
}
}
int la[N];
int main(){
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
iota(par, par + N, 0);
int n, k;
cin >> n >> k;
int u, v;
vector<pll> E;
for(int i = 1; i < n; i++){
cin >> u >> v;
G[u].pb(v);
G[v].pb(u);
E.pb({u, v});
}
DFS(u, 0, 1);
int s;
for(int i = 1; i <= n; i++){
cin >> s;
if(la[s]) Merge(la[s], i);
la[s] = i;
}
map<int, int> deg;
for(auto [u, v] : E)
if(Find(u) != Find(v))
deg[Find(u)] ++, deg[Find(v)] ++;
int cnt = 0;
for(auto [u, d] : deg) cnt += (d == 1);
// debug(cnt);
cout << (cnt + 1) / 2 << '\n';
return 0;
}
