// In the name of God
#include <bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define lc 2 * v
#define rc 2 * v + 1
#define mid (s + e) / 2
#define _sz(e) (int)e.size()
#define _all(e) e.begin() , e.end()
#define _lcm(a , b) (1ll * a * b) / __gcd(a , b)
#define ll long long
#define int long long
#define ld long double
#define pii pair <int , int>
#define pcc pair <char , char>
#define pll pair <long long , long long>
#define piii pair <int , pair <int , int>>
#define FAST ios::sync_with_stdio(0);cin.tie(0)
#pragma GCC optimize("Ofast")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,avmini,avmini2")
const int maxn = 5e5 + 10 , N = 2e6 + 10 , SQ = 320 , base = 800287 , mod = 1e9 + 7 , INF = 1e18 + 10 , lg = 22;
const ld eps = 1e-4;
int n , k , s[maxn] , mn_st[maxn] , mx_ft[maxn], st[maxn] , ft[maxn] , tme;
int mx_sub[maxn] , mn_sub[maxn] , mark[maxn] , cnt[maxn];
vector <int> edges[maxn];
void dfs1(int v , int p = -1) {
st[v] = tme++;
if(mn_st[s[v]] == -1) {
mn_st[s[v]] = st[v];
}
for (auto u : edges[v]) {
if(u != p) {
dfs1(u , v);
}
}
ft[v] = tme;
mx_ft[s[v]] = ft[v];
}
void dfs2(int v , int p = -1) {
mn_sub[v] = mn_st[s[v]] , mx_sub[v] = mx_ft[s[v]];
for (auto u : edges[v]) {
if(u != p) {
dfs2(u , v);
mn_sub[v] = min(mn_sub[v] , mn_sub[u]);
mx_sub[v] = max(mx_sub[v] , mx_sub[u]);
}
}
if(p != -1 && mn_sub[v] == st[v] && mx_sub[v] == ft[v]) {
mark[v] = 1;
}
}
void dfs3(int v , int p = -1 , int root = 0) {
for (auto u : edges[v]) {
if(u != p) {
if(mark[u]) {
cnt[root]++ , cnt[u]++;
dfs3(u , v , u);
}
else {
dfs3(u , v , root);
}
}
}
}
int32_t main() {
FAST;
cin >> n >> k;
for (int i = 0; i < n - 1; ++i) {
int x , y; cin >> x >> y;
x-- , y--;
edges[x].PB(y);
edges[y].PB(x);
}
for (int i = 0; i < n; ++i) {
cin >> s[i]; s[i]--;
}
for (int i = 0; i < k; ++i) {
mn_st[i] = -1;
}
dfs1(0);
dfs2(0);
dfs3(0);
int ans = 0;
for (int i = 0; i < n; ++i) {
ans += (cnt[i] == 1);
}
cout << (ans + 1) / 2 << '\n';
}
// Mistakes:
// * Read the problem carefully.
// * Check maxn.
// * Overflows.
