#include <bits/stdc++.h>
using namespace std;
#define form2(i, a, b) for (int i = (a); i < (b); ++i)
#define ford2(i, a, b) for (int i = (a-1); i >= (b); --i)
#define form(i, n) form2(i, 0, n)
#define ford(i, n) ford2(i, n, 0)
#define chmax(x, v) x = max(x, (v))
#define chmin(x, v) x = min(x, (v))
#define fi first
#define se second
const long long BIG = 1000000000000000000LL;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
void solve();
signed main()
{
ios::sync_with_stdio(false);
cin.tie(0);
solve();
return 0;
}
const int borne = 1000*1000 + 15;
int nbNoeuds, nbAretes, nbGroupes;
stack<int> dfsPile;
pii noeudsArete[borne];
vector<int> adjAr[borne];
int voisin(int ar, int nod)
{
pii arete = noeudsArete[ar];
if (arete.fi == nod) return arete.se;
else { return arete.fi; }
}
int dfsNum[borne], dfsLow[borne];
int arFrom[borne];
bitset<borne> estPont;
int curTemps = 0;
void dfsTarjan(int dep)
{
dfsPile.push(dep);
while (!dfsPile.empty()) {
int nod = dfsPile.top();
dfsPile.pop();
if (dfsNum[nod] == 0) {
dfsPile.push(nod);
dfsNum[nod] = ++curTemps;
dfsLow[nod] = dfsNum[nod];
for (int arete : adjAr[nod]) {
int vo = voisin(arete, nod);
if (dfsNum[vo] > 0 && arete != arFrom[nod]) {
chmin(dfsLow[nod], dfsLow[vo]);
}
if (dfsNum[vo] == 0) {
arFrom[vo] = arete;
if (nod == noeudsArete[arete].se) swap(noeudsArete[arete].fi, noeudsArete[arete].se);
dfsPile.push(vo);
}
}
} else {
for (int arete : adjAr[nod]) {
int vo = voisin(arete, nod);
if (arFrom[vo] == arete) {
chmin(dfsLow[nod], dfsLow[vo]);
}
}
}
}
}
void finaliserPonts()
{
form(i, nbAretes) {
if (dfsNum[noeudsArete[i].fi] < dfsLow[noeudsArete[i].se]) estPont[i] = true;
}
}
//vector<int> bridgeTree[borne];
char degBT[borne];
int nbComp = 0;
int indComp[borne];
bool vuFinaliser[borne];
int lst[borne];
void compresser(int dep)
{
dfsPile.push(dep);
indComp[dep] = nbComp;
while (! dfsPile.empty()) {
int nod = dfsPile.top();
dfsPile.pop();
for (int arete : adjAr[nod]) if (!estPont[arete]) {
int vo = voisin(arete, nod);
if (indComp[vo] == -1) {
indComp[vo] = nbComp;
dfsPile.push(vo);
}
}
}
}
void finaliser(int dep)
{
stack<int> dfsPile;
dfsPile.push(dep);
vuFinaliser[dep] = true;
while (!dfsPile.empty()) {
int nod = dfsPile.top();
dfsPile.pop();
int maComp = indComp[nod];
for (int arete : adjAr[nod]) if (estPont[arete]) {
int voRaw = voisin(arete, nod);
int voComp = indComp[voRaw];
if (lst[voComp] == maComp) continue;
lst[voComp] = maComp;
//bridgeTree[maComp].push_back(voComp);
if (degBT[maComp] < 2) ++degBT[maComp];
// Ajouté dans l'autre sens lors de la finalisation de voComp
}
for (int arete : adjAr[nod]) {
if (!estPont[arete]) {
int vo = voisin(arete, nod);
if (!vuFinaliser[vo]) {
vuFinaliser[vo] = true;
dfsPile.push(vo);
}
}
}
}
}
int lstGroupe[borne];
void solve()
{
fill_n(&indComp[0], borne, -1);
fill_n(&lst[0], borne, -1);
fill_n(&lstGroupe[0], borne, -1);
cin >> nbNoeuds >> nbGroupes;
nbAretes = nbNoeuds-1;
form(i, nbAretes) {
int u, v; cin >> u >> v; --u; --v;
noeudsArete[i] = {u,v};
adjAr[u].push_back(i);
adjAr[v].push_back(i);
}
form(nod, nbNoeuds) {
int groupe; cin >> groupe; --groupe;
if (lstGroupe[groupe] != -1) {
int prev = lstGroupe[groupe];
noeudsArete[nbAretes] = {nod, prev};
adjAr[nod].push_back(nbAretes);
adjAr[prev].push_back(nbAretes);
++nbAretes;
}
lstGroupe[groupe] = nod;
}
arFrom[0] = -1;
dfsTarjan(0);
finaliserPonts();
form(nod, nbNoeuds) if (indComp[nod] == -1) {
compresser(nod);
++nbComp;
}
form(nod, nbNoeuds) if (!vuFinaliser[nod]) finaliser(nod);
int nbFeuilles = 0;
form(nod, nbComp) {
//int deg = bridgeTree[nod].size();
int deg = degBT[nod];
if (deg == 1) ++nbFeuilles;
}
cout << (nbFeuilles+1) / 2 << "\n";
}
