// Judges with GCC >= 12 only needs Ofast
// #pragma GCC optimize("O3,no-stack-protector,fast-math,unroll-loops,tree-vectorize")
// MLE optimization
// #pragma GCC optimize("conserve-stack")
// Old judges
// #pragma GCC target("sse4.2,popcnt,lzcnt,abm,mmx,fma,bmi,bmi2")
// New judges. Test with assert(__builtin_cpu_supports("avx2"));
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
// Atcoder
// #pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma")
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
- insert(x),erase(x)
- find_by_order(k): return iterator to the k-th smallest element
- order_of_key(x): the number of elements that are strictly smaller
*/
#include<bits/stdc++.h>
using namespace std;
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
uniform_real_distribution<> pp(0.0,1.0);
//#define int long long
#define ld long double
#define pii pair<int,int>
#define piii pair<pii,int>
#define mpp make_pair
#define fi first
#define se second
//const int inf=1e18;
const int mod=1e9+7;
const int maxn=500005;
const int bl=650;
const int maxs=655;
const int maxm=200005;
const int maxq=500005;
const int maxl=20;
const int maxa=250000;
const int root=3;
/*
int power(int a,int n){
int res=1;
while(n){
if(n&1) res=res*a%mod;
a=a*a%mod;n>>=1;
}
return res;
}
const int iroot=power(3,mod-2);
*/
const int base=101;
namespace Tree{
vector<vector<int>> edge,Min;
vector<int> lg2,dep,L,R;
int pos;
int cmp(int u,int v){
return (dep[u]<dep[v]?u:v);
}
int lca(int u,int v){
u=L[u];v=L[v];
if(u>v) swap(u,v);
int p=lg2[v-u+1];
return cmp(Min[u][p],Min[v-(1<<p)+1][p]);
}
int dist(int u,int v){
return dep[u]+dep[v]-2*dep[lca(u,v)];
}
void dfs(int u,int p){
L[u]=++pos;Min[pos][0]=u;
dep[u]=dep[p]+1;
for(int v:edge[u]){
if(v==p) continue;
dfs(v,u);Min[++pos][0]=u;
}
R[u]=pos;
}
void init(int n){
lg2.assign(2*n+1,0);
dep.assign(n+1,0);
L.assign(n+1,0);
R.assign(n+1,0);
edge.resize(n+1);
Min.assign(2*n+1,vector<int>(maxl,0));
}
void build(int n){
init(n);
for(int i=1;i<n;i++){
int u,v;cin >> u >> v;
edge[u].push_back(v);
edge[v].push_back(u);
}
dfs(1,0);
for(int i=2;i<=pos;i++) lg2[i]=lg2[i/2]+1;
for(int i=1;i<20;i++){
for(int j=1;j<=(pos-(1<<i)+1);j++) Min[j][i]=cmp(Min[j][i-1],Min[j+(1<<(i-1))][i-1]);
}
}
}
int num[maxn],p[maxn],par[maxn],cnt[maxn];
int findpar(int u){
if(u!=par[u]) return par[u]=findpar(par[u]);
return u;
}
void unions(int u,int v){
u=findpar(u);v=findpar(v);
if(u!=v) par[v]=u;
}
void add(int u,int v){
num[u]++;num[v]++;
num[Tree::lca(u,v)]-=2;
}
void dfs(int u,int p){
for(int v:Tree::edge[u]){
if(v==p) continue;
dfs(v,u);num[u]+=num[v];
}
if(num[u]>=1 && p) unions(u,p);
}
void dfs2(int u,int p){
if(num[u]==0 && p){
cnt[findpar(u)]++;
cnt[findpar(p)]++;
}
for(int v:Tree::edge[u]){
if(v==p) continue;
dfs2(v,u);
}
}
void solve(){
int n,k;cin >> n >> k;
for(int i=1;i<=n;i++) par[i]=i;
Tree::build(n);
for(int i=1;i<=n;i++){
int s;cin >> s;
if(p[s]) add(i,p[s]);
p[s]=i;
}
dfs(1,0);dfs2(1,0);
int leaf=0;
for(int i=1;i<=n;i++) leaf+=(cnt[i]==1);
cout << (leaf+1)/2 << '\n';
}
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);cout.tie(NULL);
int test=1;//cin >> test;
while(test--) solve();
}
