#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>
#ifdef DEBUG
#include <time.h>
#endif
#define all(a) (a).begin(), (a).end()
#define rev(a) (a).rbegin(), (a).rend()
#define F first
#define S second
int recur_depth = 0;
#ifdef DEBUG
#define dbg(x) \
{ \
++recur_depth; \
auto x_ = x; \
--recur_depth; \
cerr << string(recur_depth, '\t') << "\e[91m" << __func__ << ":" \
<< __LINE__ << "\t" << #x << " = " << x_ << "\e[39m" << endl; \
}
#else
#define dbg(x)
#endif
using namespace std;
using namespace __gnu_pbds;
typedef pair<int, int> ii;
typedef long long ll;
typedef long double ld;
typedef pair<ll, ll> llll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<pair<int, int>> vii;
typedef vector<vii> vvii;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pair<ll, ll>> vll;
typedef vector<vll> vvll;
typedef vector<bool> vb;
template <class type1>
using ordered_set = tree<type1, null_type, less<type1>, rb_tree_tag,
tree_order_statistics_node_update>;
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p) {
return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<
!is_same<T_container, string>::value,
typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v) {
os << '{';
string sep;
for (const T &x : v)
os << sep << x, sep = ", ";
return os << '}';
}
const ll MOD = 1e9 + 7;
// const ll MOD = 998244353;
const ll INF = 1e9;
const ld EPS = 1e-9;
const int MAXN = 5e5 + 1;
const int MAXLG = 22;
int in[MAXN], out[MAXN];
int timer = 0;
int p[MAXN][MAXLG];
vvi g(MAXN);
void dfs(int v, int e) {
in[v] = timer++;
p[v][0] = e;
for (int j = 1; j <= 20; j++)
p[v][j] = p[p[v][j - 1]][j - 1];
for (int to : g[v]) {
if (to == e)
continue;
dfs(to, v);
}
out[v] = timer++;
}
bool isancestor(int u, int v) { return in[u] <= in[v] && out[u] >= out[v]; }
int lca(int u, int v) {
if (isancestor(u, v))
return u;
if (isancestor(v, u))
return v;
for (int j = 20; j >= 0; j--) {
if (!isancestor(p[u][j], v))
u = p[u][j];
}
return p[u][0];
}
vi sz(MAXN), a(MAXN);
int c = 0;
void dfs2(int v, int e) {
sz[v] = 1;
for (int to : g[v]) {
if (to == e)
continue;
dfs2(to, v);
sz[v] += sz[to];
}
sz[v] -= a[v];
if (sz[v] == 0)
c++;
}
int cnt[MAXN];
int leaf = 0;
void ansdfs(int v, int cur, int e) {
if (sz[v] == 0 && cur != v)
cnt[v]++, cnt[cur]++;
if (sz[v] == 0)
cur = v;
for (int to : g[v]) {
if (to != e)
ansdfs(to, cur, v);
}
if (cnt[v] == 1)
leaf++;
}
void solve() {
int n;
cin >> n;
int k;
cin >> k;
vector<vector<int>> vec(k + 1);
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
dfs(1, 1);
for (int i = 1; i <= n; ++i) {
int x;
cin >> x;
vec[x].push_back(i);
}
for (int i = 1; i <= k; i++) {
if (vec[i].empty())
continue;
int lc = vec[i][0];
for (int to : vec[i])
lc = lca(lc, to);
a[lc] += vec[i].size();
}
dfs2(1, 1);
if (c == 1)
cout << 0 << "\n";
else {
ansdfs(1, 1, 1);
cout << (leaf + 1) / 2 << "\n";
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(NULL);
clock_t start = clock();
int test_cases = 1;
// cin >> test_cases;
while (test_cases--)
solve();
#ifdef DEBUG
cerr << fixed << setprecision(10)
<< "\nTime Taken: " << (double)(clock() - start) / CLOCKS_PER_SEC
<< "s\n";
#endif
return 0;
}
