#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ar array
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int n, k; cin >> n >> k;
vector <vector<int>> adj(n);
for ( int i = 0; i + 1 < n; i++ ){
int u, v; cin >> u >> v;
--u, --v;
adj[u].pb(v);
adj[v].pb(u);
}
vector <int> s(n);
for ( auto &x: s ){
cin >> x; --x;
}
vector <int> tin(n), tout(n);
vector <ar<int,2>> f(k, {n, -1});
int ct = 0;
auto trav = [&](auto trav, int u, int p) -> void{
tin[u] = ++ct;
if ( f[s[u]][0] == n ) f[s[u]][0] = ct;
for ( auto &v: adj[u] ){
if ( v != p ) trav(trav, v, u);
} tout[u] = ct;
f[s[u]][1] = ct;
};
trav(trav, 0, -1);
vector <ar<int,2>> q(n);
vector <int> bad(n);
auto dfs = [&](auto dfs, int u, int p) -> void{
q[u] = f[s[u]];
for ( auto &v: adj[u] ){
if ( v != p ){
dfs(dfs, v, u);
q[u][0] = min(q[u][0], q[v][0]);
q[u][1] = max(q[u][1], q[v][1]);
}
}
if ( tin[u] <= q[u][0] && tout[u] >= q[u][1] ){
bad[u] = 1;
}
};
dfs(dfs, 0, -1);
vector <int> sub(n);
bad[0] = 0;
auto cals = [&](auto cals, int u, int p) -> void{
sub[u] = bad[u];
for ( auto &v: adj[u] ){
if ( v != p ){
cals(cals, v, u);
sub[u] += sub[v];
}
}
};
cals(cals, 0, -1);
int num = 0;
for ( int u = 1; u < n; u++ ){
if ( !bad[u] ) continue;
if ( sub[u] == sub[0] || sub[u] == 1 ){
num += 1;
}
}
cout << (num + 1) / 2;
cout << '\n';
}
