#include <bits/stdc++.h>
#define owo(i,a, b) for(int i=(a); i<(b); ++i)
#define uwu(i,a, b) for(int i=(a)-1; i>=(b); --i)
#define senpai push_back
#define ttgl pair<int, int>
#define ayaya cout<<"debug"<<endl
using namespace std;
using ll = long long;
using ld = long double;
const ll MOD = 998244353;
const double PI = acos(-1);
const int INF = 0x3f3f3f3f;
const int NINF = 0x3f3f3f40;
const ll INFLL = 0x3f3f3f3f3f3f3f3f;
const ll NINFLL = 0x3f3f3f3f3f3f3f40;
const int mxN = 500001;
vector<int> adj[mxN];
int n, k;
int state[mxN];
int high[mxN];
int depth[mxN];
int val[mxN];
int par[mxN];
bool flag[mxN];
int best[mxN];
int ans = 0;
int cnt =0;
ttgl edges[mxN];
int dsu[mxN];
int sz[mxN];
map<int, int> mp[mxN];
int find(int a){return dsu[a]==a ? a : dsu[a] = find(dsu[a]);}
void merge(int a, int b) {
a = find(a);b = find(b);
if(sz[b]<sz[a]) swap(a, b);
dsu[a] = b;
sz[b]+=sz[a];
}
void comb(int u, int v) {
if(mp[u].size()<mp[v].size()) {
swap(mp[u], mp[v]);
}
for(auto p: mp[v]) {
mp[u][p.first]+=p.second;
if(mp[u][p.first]==state[p.first]) {
mp[u].erase(p.first);
}
}
}
void dfs(int u, int p) {
par[u] = p;
mp[u][val[u]]++;
for(int v: adj[u]) {
if(v==p)continue;
depth[v] =depth[u]+1;
dfs(v, u);
comb(u, v);
}
for(auto p: mp[u]) {
if(mp[u][p.first]==state[p.first]) {
mp[u].erase(p.first);
}
}
if(!mp[u].empty()) {
//cout<<u<<"\n";
merge(val[u], val[p]);
}
}
int deg[mxN];
int main()
{
//freopen("filename.in", "r", stdin);
//freopen("filename.out", "w", stdout);
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
cin.tie(0)->sync_with_stdio(0);
cin>>n>>k;
int a, b;
owo(i, 0, n-1) {
cin>>a>>b;
a--; b--;
edges[i] = {a, b};
adj[a].senpai(b);
adj[b].senpai(a);
}
owo(i, 0, n) {
cin>>a;
a--;
val[i] = a;
state[a]++;
}
owo(i, 0, k) {
dsu[i] = i;
sz[i] = 1;
//cout<<state[i]<<"\n";
}
dfs(0, 0);
for(auto p: edges) {
if(find(val[p.first])!=find(val[p.second])) {
deg[find(val[p.first])]++;
deg[find(val[p.second])]++;
}
}
owo(i, 0, k){
if(deg[i]==1) ans++;
}
//cout<<ans<<"\n";
cout<<(ans+1)/2<<"\n";
return 0;
}
