#include <bits/stdc++.h>
#define pii pair <int, int>
#define fi first
#define se second
using namespace std;
const int maxN = 5e5 + 5;
int S[maxN], par[maxN], sz[maxN];
vector <int> adj[maxN];
int last[maxN];
int cnt[maxN];
int up[maxN], depth[maxN];
const int BUFFER_SIZE = 1 << 20;
char input_buffer[BUFFER_SIZE];
int input_pos = 0, input_len = 0;
inline char nextChar() {
if (input_pos == input_len) {
input_pos = 0;
input_len = fread(input_buffer, 1, BUFFER_SIZE, stdin);
if (input_len == 0) return EOF;
}
return input_buffer[input_pos++];
}
inline void fast_read(int &x) {
x = 0;
char c;
bool neg = false;
do {
c = nextChar();
} while (c != '-' && (c < '0' || c > '9'));
if (c == '-') {
neg = true;
c = nextChar();
}
while (c >= '0' && c <= '9') {
x = x * 10 + (c - '0');
c = nextChar();
}
if (neg) x = -x;
}
inline void init (int n) {
for (int i = 1; i <= n; i ++) {
par[i] = i;
sz[i] = 1;
}
}
int getRoot (int u) {
if (par[u] == u) {
return u;
}
return (par[u] = getRoot (par[u]));
}
inline void join (int u, int v) {
u = getRoot (u);
v = getRoot (v);
if (u == v) {
return;
}
if (sz[u] < sz[v]) {
swap (u, v);
}
par[v] = u;
sz[u] += sz[v];
return;
}
inline void merge (int u, int v) {
while (u != v) {
//cout << u << ' ' << v << '\n';
if (depth[u] > depth[v]) {
swap (u, v);
}
join (v, up[v]);
v = up[v];
}
}
void dfs (int u, int p) {
up[u] = p;
for (auto v : adj[u]) {
if (v == p) {
continue;
}
depth[v] = depth[u] + 1;
dfs (v, u);
}
}
int main () {
ios_base :: sync_with_stdio (0);
cin.tie (0);
int n, k;
fast_read (n);
fast_read (k);
init (n);
for (int i = 1; i < n; i ++) {
int u, v;
fast_read (u);
fast_read (v);
adj[u].push_back (v);
adj[v].push_back (u);
}
dfs (1, 0);
for (int i = 1; i <= n; i ++) {
fast_read (S[i]);
if (last[S[i]] != 0) {
merge (i, S[i]);
}
last[S[i]] = i;
}
for (int u = 1; u <= n; u ++) {
for (auto v : adj[u]) {
int i = getRoot (u);
int j = getRoot (v);
if (i != j) {
cnt[i] ++;
}
}
}
int res = 0;
for (int i = 1; i <= n; i ++) {
res += (cnt[i] == 1);
}
cout << (res + 1) / 2;
return 0;
}
