#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define y1 zck_is_king
#define pii pair<int, int>
#define ull unsigned ll
#define f first
#define s second
#define ALL(x) x.begin(),x.end()
#define SZ(x) (int)x.size()
#define SQ(x) (x)*(x)
#define MN(a,b) a = min(a,(__typeof__(a))(b))
#define MX(a,b) a = max(a,(__typeof__(a))(b))
#define pb push_back
#define REP(i,n) for (int i = 0; i<n; ++i)
#define RREP(i,n) for (int i = n-1; i>=0; --i)
#define REP1(i,n) for (int i = 1; i<=n; ++i)
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#ifdef BALBIT
#define IOS()
#define bug(...) fprintf(stderr,"#%d (%s) = ",__LINE__,#__VA_ARGS__),_do(__VA_ARGS__);
template<typename T> void _do(T &&x){cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S &&...y){cerr<<x<<", ";_do(y...);}
#else
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0);
#define endl '\n'
#define bug(...)
#endif
const int iinf = 1e9+10;
const ll inf = 1ll<<60;
const ll mod = 1e9+7 ;
void GG(){cout<<"0\n"; exit(0);}
ll mpow(ll a, ll n, ll mo = mod){ // a^n % mod
ll re=1;
while (n>0){
if (n&1) re = re*a %mo;
a = a*a %mo;
n>>=1;
}
return re;
}
ll inv (ll b, ll mo = mod){
if (b==1) return b;
return (mo-mo/b) * inv(mo%b,mo) % mo;
}
const int maxn = 1e5+5;
vector<int> g[maxn];
int dpar[maxn];
int par[maxn], dep[maxn];
void dfs(int v, int p) {
par[v] = p;
for (int u : g[v]) {
if (u != p) {
dep[u] = dep[v] + 1;
dfs(u,v);
}
}
}
vector<int> where[maxn];
int find (int x ) {return x == dpar[x] ? x : dpar[x] = find(dpar[x]); }
void mrg(int a,int b ) {
a = find(a); b = find(b);
if (dep[a] > dep[b]) swap(a,b); // a is new root;
dpar[b] = a;
}
set<int> adj[maxn];
signed main(){
IOS();
int n,k; cin>>n>>k;
vector<pii> E;
REP(i,n-1) {
int a,b; cin>>a>>b; --a; --b;
E.pb({a,b});
g[a].pb(b); g[b].pb(a);
}
dfs(0, -1);
REP(i,n) dpar[i ]= i;
REP(i,n) {
int x; cin>>x;
where[x-1].pb(i);
}
REP(c, k) {
int tmp = where[c][0];
tmp = find(tmp);
for (int i = 1; i<SZ(where[c]); ++i) {
int v = where[c][i];
v = find(v);
while (v != tmp) {
if (dep[v] < dep[tmp]) swap(v, tmp);
// move v
mrg(v, par[v]);
v = find(v);
bug(v, tmp);
}
}
}
for (pii p : E) {
if(find (p.f) != find(p.s)) {
adj[find(p.f)].insert(find(p.s));
adj[find(p.s)].insert(find(p.f));
}
}
int lf = 0;
REP(i,n) {
if (find (i) == i) {
if (SZ(adj[i]) == 1) lf++;
}
}
assert(lf != 1);
cout<<(lf+1)/2<<endl;
}
