#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(a, b) for(int a = 0; a < (b); ++a)
#define st first
#define nd second
#define pb push_back
#define all(a) a.begin(), a.end()
const int LIM=5e5+7;
vector<int>V[LIM], P[LIM];
int T[LIM], odl[LIM], F[LIM], oc[LIM], deg[LIM];
void DFS(int x, int o) {
for(auto i : V[x]) if(i!=o) {
odl[i]=odl[x]+1;
oc[i]=x;
DFS(i, x);
}
}
int fnd(int x) {
if(F[x]==x) return x;
return F[x]=fnd(F[x]);
}
void uni(int a, int b) {
if(fnd(a)==fnd(b)) return;
F[fnd(b)]=fnd(a);
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int n, k;
cin >> n >> k;
rep(i, n-1) {
int a, b;
cin >> a >> b; --a; --b;
V[a].pb(b);
V[b].pb(a);
}
DFS(0, 0);
rep(i, n) {
cin >> T[i]; --T[i];
P[T[i]].pb(i);
F[i]=i;
}
rep(i, k) {
set<pair<int,int>>S;
for(auto j : P[i]) S.insert({odl[fnd(j)], fnd(j)});
while(S.size()>1) {
auto it=S.end(); --it;
auto p=*it;
S.erase(it);
uni(oc[p.nd], p.nd);
S.insert({odl[fnd(p.nd)], fnd(p.nd)});
}
}
rep(i, n) for(auto j : V[i]) if(fnd(i)!=fnd(j)) ++deg[fnd(j)];
int ans=0;
rep(i, n) if(deg[i]==1) ++ans;
cout << (ans+1)/2 << '\n';
}
