#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define int long long
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FORD(i, a, b) for (int i = (b); i >= (a); i --)
#define REP(i, a) for (int i = 0; i < (a); ++i)
#define REPD(i, a) for (int i = (a) - 1; i >= 0; --i)
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
constexpr ll LINF = (1ll << 60);
constexpr int INF = (1ll << 30);
constexpr int Mod = 1e9 + 7;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
/*
Phu Trong from Nguyen Tat Thanh High School for gifted student
*/
template <class X, class Y>
bool minimize(X &x, const Y &y){
X eps = 1e-9;
if (x > y + eps) {x = y; return 1;}
return 0;
}
template <class X, class Y>
bool maximize(X &x, const Y &y){
X eps = 1e-9;
if (x + eps < y) {x = y; return 1;}
return 0;
}
#define MAX 500005
int numNode, numState, label[MAX];
vector<int> G[MAX];
int cntState[MAX];
map<int, int> cnt[MAX];
int ans = 0;
int lab[MAX];
int fp(int u){
return (lab[u] < 0 ? u : lab[u] = fp(lab[u]));
}
bool joint (int u, int v){
u = fp(u), v = fp(v);
if(u == v) return false;
if(lab[u] > lab[v]) swap(u, v);
lab[u] += lab[v];
lab[v] = u;
return true;
}
void dfs(int u, int p = -1){
cnt[u][label[u]] = 1;
if(cnt[u][label[u]] == cntState[label[u]]){
cnt[u].erase(cnt[u].find(label[u]));
}
for (int&v : G[u]) if(v ^ p){
dfs(v, u);
if((int)cnt[u].size() < (int)cnt[v].size()){
swap(cnt[u], cnt[v]);
}
for (auto&x : cnt[v]){
cnt[u][x.first] += x.second;
if(cntState[x.first] == cnt[u][x.first]){
cnt[u].erase(cnt[u].find(x.first));
}
}
}
if(p != -1){
if(!cnt[u].empty()){
joint(u, p);
}
}
}
int deg[MAX];
void process(void){
cin >> numNode >> numState;
for (int i = 1; i < numNode; ++i){
int u, v; cin >> u >> v;
G[u].emplace_back(v);
G[v].emplace_back(u);
}
for (int i = 1; i <= numNode; ++i){
cin >> label[i];
cntState[label[i]]++;
}
for (int i = 1; i <= numNode; ++i) lab[i] = -1;
dfs(1);
for (int u = 1; u <= numNode; ++u){
for (int&v : G[u]) {
if(fp(u) != fp(v)){
++deg[u];
}
}
}
for (int u = 1; u <= numNode; ++u) ans += (deg[u] == 1);
cout << (ans + 1) / 2;
}
signed main(){
#define name "Whisper"
cin.tie(nullptr) -> sync_with_stdio(false);
// freopen(name".inp", "r", stdin);
// freopen(name".out", "w", stdout);
process();
return (0 ^ 0);
}
