//#pragma GCC optimize("Ofast,unroll-loops,O3")
//#pragma GCC optimize("avx,avx2,sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,fma,tune=native")
#include<bits/stdc++.h>
//#include<bits/extc++.h>
//#pragma pack(1)
#define fast ios::sync_with_stdio(0); cin.tie(0);
#define int long long
#define pii pair<int,int>
#define x first
#define y second
#define N 500015
using namespace std;
//using namespace __gnu_pbds;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//typedef tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update> order_multiset;
//typedef tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> order_set;
struct DSU{
int boss[N],sz[N],group=0;
void init(int n){
group=n;
for (int i=0;i<=n+1;i++){
boss[i]=i;
sz[i]=1;
}
}
int find(int x){
if (boss[x]==x) return x;
return boss[x]=find(boss[x]);
}
void Merge(int a,int b){
int ra=find(a),rb=find(b);
if (ra==rb) return;
group--;
if (sz[ra]<sz[rb]) swap(ra,rb);
sz[ra]+=sz[rb];
boss[rb]=ra;
}
}d;
int n,k,fa[N],dep[N],is[N],deg[N],cnt=0;
vector<int>g[N],all[N];
void dfs(int p,int lp){
fa[p]=lp; dep[p]=dep[lp]+1;
for (auto i:g[p]){
if (i!=lp)
dfs(i,p);
}
}
void merge_path(int a,int b){
vector<int>path;
// cout<<"Go "<<a<<" "<<b<<'\n';
while (a!=b){
if (dep[a]>=dep[b]){
path.push_back(a);
d.Merge(is[a],is[fa[a]]);
a=fa[a];
}
else {
path.push_back(b);
d.Merge(is[b],is[fa[b]]);
b=fa[b];
}
}
for (auto i:path)
fa[i]=a;
}
signed main(){
fast
cin>>n>>k;
d.init(k);
vector<pii>edge;
for (int i=1;i<n;i++){
int a,b; cin>>a>>b;
g[a].push_back(b);
g[b].push_back(a);
edge.push_back({a,b});
}
for (int i=1;i<=n;i++){
cin>>is[i];
all[is[i]].push_back(i);
}
dfs(1,1);
for (int i=1;i<=k;i++){
for (int j=1;j<all[i].size();j++)
merge_path(all[i][j-1],all[i][j]);
}
for (auto i:edge){
if (d.find(is[i.x])!=d.find(is[i.y])){
deg[d.find(is[i.x])]++;
deg[d.find(is[i.y])]++;
}
}
for (int i=1;i<=k;i++)
cnt+=(deg[i]==1);
cout<<(cnt+1)/2<<'\n';
}
