#include<bits/stdc++.h>
using namespace std;
#define ii pair<int,int>
#define fi first
#define se second
#define eb emplace_back
const int N=1000100;
int n,k,a[N],last[N];
int num[N],low[N],Time; bool bridge[N];
int idc[N],deg[N],curc;
vector<ii> ia[N];
void dfs(int u, int lid){
num[u]=low[u]=++Time;
for(auto [v,id]:ia[u]) if(id!=lid){
if(!num[v]){
dfs(v,id);
low[u]=min(low[u],low[v]);
if(low[v]>num[u]){
bridge[id]=true;
}
}
else{
low[u]=min(low[u],num[v]);
}
}
}
void dfs2(int u){
idc[u]=curc;
for(auto [v,id]:ia[u]){
if(bridge[id]){
if(idc[v]){
deg[idc[u]]++; deg[idc[v]]++;
}
continue;
}
if(!idc[v]) dfs2(v);
}
}
int main(){
cin>>n>>k;
for(int i=1; i<n; ++i){
int u,v; cin>>u>>v;
ia[u].eb(v,i);
ia[v].eb(u,i);
}
for(int i=1; i<=n; ++i){
cin>>a[i];
if(last[a[i]]!=0){
ia[last[a[i]]].eb(i,i+n);
ia[i].eb(last[a[i]],i+n);
}
last[a[i]]=i;
}
dfs(1,0);
for(int i=1; i<=n; ++i) if(!idc[i]){
++curc;
dfs2(i);
}
int res=0;
for(int i=1; i<=curc; ++i) res+=deg[i]==1;
cout<<(res+1)/2<<'\n';
}
