#include<bits/stdc++.h>
#define st first
#define nd second
#define pb push_back
#define ppb pop_back
#define ii pair<int,int>
#define ll long long
#define orta ((bas+son)>>1)
#define sz(x) ((int)x.size())
#define all(x) x.begin(),x.end()
#define umin(x,y) x=min(x,y)
#define umax(x,y) x=max(x,y)
#define inf 2000000000000000
#define N 500005
#define MOD 998244353
#define KOK 700
using namespace std;
int n,k,root,cnt;
int sub[N],has[N],h[N],dad[N],u[N],s[N],rem[N];
vector<int> v[N],v2[N];
void dfs6(int node,int ata) {
for(int i:v2[node]) {
if(i==ata) continue ;
dfs6(i,node);
rem[node]+=rem[i];
}
if(sz(v2[node])==1) {
rem[node]=1;
return ;
}
cnt+=rem[node]/2;
rem[node]&=1;
}
int find(int x) {return dad[x]==x?x:(dad[x]=find(dad[x]));}
void merge(int x,int y) {
while((x=find(x))!=find(root)) {
dad[x]=find(u[x]);
x=dad[x];
}
while((y=find(y))!=find(root)) {
dad[y]=find(u[y]);
y=dad[y];
}
}
void add(int node) {
if(!has[s[node]]) has[s[node]]=node;
}
void ask(int node) {
if(!has[s[node]]) return ;
merge(has[s[node]],node);
}
void dfs5(int node,int ata) {
has[s[node]]=0;
for(int i:v[node]) {
if(i==ata) continue ;
dfs5(i,node);
}
}
void dfs4(int node,int ata) {
add(node);
for(int i:v[node]) {
if(i==ata) continue ;
dfs4(i,node);
}
}
void dfs3(int node,int ata) {
ask(node);
for(int i:v[node]) {
if(i==ata) continue ;
dfs3(i,node);
}
}
void dfs2(int node,int ata,bool up) {
for(int i:v[node]) {
if(i==ata || i==h[node]) continue ;
dfs2(i,node,0);
}
if(h[node]) dfs2(h[node],node,1);
ask(root=node);
add(root=node);
for(int i:v[node]) {
if(i==ata || i==h[node]) continue ;
dfs3(i,node);
dfs4(i,node);
}
if(!up) {
dfs5(node,ata);
}
}
void dfs(int node,int ata) {
sub[node]=1;
for(int i:v[node]) {
if(i==ata) continue ;
dfs(i,node);
sub[node]+=sub[i];
if(!h[node]) h[node]=i;
else if(sub[i]>sub[h[node]]) h[node]=i;
}
u[node]=ata;dad[node]=node;
}
int main() {
scanf("%d %d",&n,&k);
for(int i=1;i<n;i++) {
int x,y;
scanf("%d %d",&x,&y);
v[x].pb(y);
v[y].pb(x);
}
for(int i=1;i<=n;i++) {
scanf("%d",s+i);
}
dfs(1,0);
dfs2(1,0,0);
map<ii,int> pr;
for(int i=1;i<=n;i++) {
for(auto x:v[i]) {
if(find(i)!=find(x) && !pr.count({find(i),find(x)})) {
pr[{find(i),find(x)}]=pr[{find(x),find(i)}]=1;
v2[find(i)].pb(find(x));
v2[find(x)].pb(find(i));
}
}
}
dfs6(find(1),0);
printf("%d",cnt+rem[find(1)]);
}
