#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define int ll
#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define REP(i, n) FOR(i, 0, n)
#define REP1(i, n) FOR(i, 1, n+1)
#define RREP(i, n) for (int i = (n)-1; i >= 0; i--)
#define RREP1(i, n) for (int i = (n); i >= 1; i--)
#define pii pair<int, int>
#define f first
#define s second
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) (int)((x).size())
const ll maxn = 5e5+5;
const ll inf = (1ll<<60);
int n, k;
vector<int> g[maxn], g2[maxn];
vector<int> col(maxn), par(maxn);
int fin(int a){
if (a == par[a]) return a;
return par[a] = fin(par[a]);
}
void merg(int a, int b){
a = fin(a); b = fin(b);
par[a] = b;
}
map<int, int> st[maxn]; // oo
vector<int> mx(maxn), crs(maxn), sz(maxn);
void dfs(int x, int prev){
sz[x]++;
pii cid = {-1, -1};
int u;
REP(i, SZ(g[x])){
u = g[x][i];
if (u == prev) continue;
dfs(u, x);
cid = max(cid, {sz[u], u});
sz[x] += sz[u];
}
if (cid.s != -1) {
st[x].swap(st[cid.s]);
crs[x] = crs[cid.s];
}
REP(i, SZ(g[x])){
u = g[x][i];
if (u == prev || u == cid.s) continue;
for (auto p:st[u]){
if (st[x][p.f] == 0) crs[x]++;
st[x][p.f] += p.s;
if (st[x][p.f] == mx[p.f]) crs[x]--;
}
st[u].clear();
}
if (st[x][col[x]] == 0) crs[x]++;
st[x][col[x]]++;
if (st[x][col[x]] == mx[col[x]]) crs[x]--;
if (crs[x] > 0) {
merg(x, prev);
//cout<<x<<' '<<prev<<endl;
}
}
signed main(){
ios::sync_with_stdio(false), cin.tie(0), cout.tie(0);
cin>>n>>k;
REP1(i, n) par[i] = i;
REP(i, n-1){
int u, v; cin>>u>>v;
g[u].pb(v);
g[v].pb(u);
}
REP1(i, n){
cin>>col[i];
mx[col[i]]++;
}
dfs(1, -1);
vector<int> deg(n+1);
REP1(i, n){
for (auto u:g[i]) if (fin(u) != fin(i) && u < i) deg[fin(i)]++, deg[fin(u)]++; // so it only counts once
}
int lf = 0;
REP1(i, n) if (deg[i] == 1) lf++;
cout<<(lf/2)+(lf&1)<<endl;
}
