#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
typedef pair<db,db> pd;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<db> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;
#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5;
const ll INF = 1e18;
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1};
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
template<class T> bool ckmin(T& a, const T& b) {
return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) {
return a < b ? a = b, 1 : 0; }
int pct(int x) { return __builtin_popcount(x); }
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x))
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0
int fstTrue(function<bool(int)> f, int lo, int hi) {
hi ++; assert(lo <= hi); // assuming f is increasing
while (lo < hi) { // find first index such that f is true
int mid = (lo+hi)/2;
f(mid) ? hi = mid : lo = mid+1;
}
return lo;
}
// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);
template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }
template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }
// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) {
stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) {
str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
str res = ""; F0R(i,SZ) res += char('0'+b[i]);
return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
bool fst = 1; str res = "{";
for (const auto& x: v) {
if (!fst) res += ", ";
fst = 0; res += ts(x);
}
res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
return "("+ts(p.f)+", "+ts(p.s)+")"; }
// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) {
pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) {
pr(h); if (sizeof...(t)) pr(" "); ps(t...); }
// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << ts(h); if (sizeof...(t)) cerr << ", ";
DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif
// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
unsyncIO();
// cin.exceptions(cin.failbit);
// throws exception when do smth illegal
// ex. try to read letter into int
if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}
/**
* Description: Calculates least common ancestor in tree
* with root $R$ using binary jumping.
* Time: O(N\log N) build, O(\log N) query
* Memory: O(N\log N)
* Source: USACO Camp
* Verification: Debug the Bugs
*/
template<int SZ> struct LCA {
static const int BITS = 32-__builtin_clz(SZ);
int N, R = 1, par[BITS][SZ], depth[SZ], S[SZ], minb[SZ], blca[SZ]; vi adj[SZ], adj2[SZ], children[SZ]; bool forb[SZ];
/// INITIALIZE
void ae(int u, int v) { adj[u].pb(v), adj[v].pb(u); }
void dfs(int u, int prv){
depth[u] = depth[par[0][u] = prv]+1;
children[prv].pb(u);
trav(v,adj[u]) if (v != prv) dfs(v,u); }
void init(int _N) {
N = _N; dfs(R,0);
FOR(k,1,BITS) FOR(i,1,N+1)
par[k][i] = par[k-1][par[k-1][i]];
}
/// QUERY
int getPar(int a, int b) {
R0F(k,BITS) if (b&(1<<k)) a = par[k][a];
return a; }
int lca(int u, int v){
if (depth[u] < depth[v]) swap(u,v);
u = getPar(u,depth[u]-depth[v]);
R0F(k,BITS) if (par[k][u] != par[k][v])
u = par[k][u], v = par[k][v];
return u == v ? u : par[0][u];
}
int dist(int u, int v) { // # edges on path
return depth[u]+depth[v]-2*depth[lca(u,v)]; }
//NEW OPERATIONS
int findMin(int node = 1){
int val = depth[blca[S[node]]];
for(auto u: children[node]){
ckmin(val, findMin(u));
}
assert(val <= depth[node]);
if(val == depth[node]){
forb[node] = 1;
}
minb[node] = val;
return val;
}
void genbPars(int node = 1, int t = 1){
for(auto u: children[node]){
if(forb[u] == 1){
adj2[u].pb(t);
adj2[t].pb(u);
genbPars(u, u);
}
else{
genbPars(u, t);
}
}
}
int getLeaves(){
int leaves = 0;
for(int i = 1; i <= N; i++){
if(forb[i] == 0) continue;
if(sz(adj2[i]) == 1){
leaves++;
}
}
return leaves;
}
};
LCA<500005> tr;
int blca[500005];
int main() {
setIO();
int N, K;
cin >> N >> K;
for(int i = 1; i <= N-1; i++){
int A, B;
cin >> A >> B;
tr.ae(A, B);
}
tr.init(N);
for(int i = 1; i <= N; i++){
cin >> tr.S[i];
if(tr.blca[tr.S[i]] == 0){
tr.blca[tr.S[i]] = i;
}
else{
tr.blca[tr.S[i]] = tr.lca(i, tr.blca[tr.S[i]]);
}
}
tr.findMin(); //find min-depth blca of children and self, mark forbidden vertices
tr.genbPars(); //don't go to forbidden vertices, keep track of the forbidden vertex for each vertex, generate parents
int num = tr.getLeaves(); //for each forbidden vertex, look at adj list and count leaves
int ans = (num+1)/2;
ps(ans);
// you should actually read the stuff at the bottom
}
/* stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
*/
