#include <bits/stdc++.h>
using namespace std;
const int N = 500'000;
int n, k, s[N + 10], par[N + 10];
int tim, st[N + 10], ft[N + 10];
int mnPack[N + 10], mxPack[N + 10];
int mn[N + 10], mx[N + 10], deg[N + 10];
vector<int> adj[N + 10], pack[N + 10];
vector<pair<int, int>> edge;
void readInput() {
cin >> n >> k;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
cin >> s[i];
pack[s[i]].push_back(i);
}
fill(par + 1, par + n + 1, -1);
}
void dfs(int u = 1, int par = 0) {
st[u] = ++tim;
for (auto v: adj[u])
if (v != par)
dfs(v, u);
ft[u] = tim;
}
void calcMinMax() {
for (int i = 1; i <= k; i++) {
mnPack[i] = N + 10;
mxPack[i] = -1;
for (auto u: pack[i]) {
mnPack[i] = min(mnPack[i], st[u]);
mxPack[i] = max(mxPack[i], st[u]);
}
}
}
int getPar(int u) {
return (par[u] < 0? u: (par[u] = getPar(par[u])));
}
bool merg(int u, int v) {
if ((u = getPar(u)) == (v = getPar(v)))
return false;
if (par[v] < par[u])
swap(u, v);
par[u] += par[v];
par[v] = u;
return true;
}
void dfsEdge(int u = 1, int par = 0) {
mn[u] = mnPack[s[u]];
mx[u] = mxPack[s[u]];
for (auto v: adj[u])
if (v != par) {
dfsEdge(v, u);
mn[u] = min(mn[u], mn[v]);
mx[u] = max(mx[u], mx[v]);
}
if (par) {
if (st[u] <= mn[u] && mx[u] <= ft[u])
edge.push_back({u, par});
else
merg(u, par);
}
//cout << u << ' ' << par << ": " << st[u] << ' ' << ft[u] << " - " << mn[u] << mx[u] << endl;
}
void calcDeg() {
for (auto [u, v]: edge) {
deg[getPar(u)]++;
deg[getPar(v)]++;
}
}
void calcAns() {
int cntLeaf = 0;
for (int i = 1; i <= n; i++)
if (i == getPar(i) && deg[i] == 1)
cntLeaf++;
cout << (cntLeaf + 1) / 2 << flush;
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
readInput();
dfs();
calcMinMax();
dfsEdge();
calcDeg();
calcAns();
return 0;
}
