//khodaya khodet komak kon
# pragma GCC target ("avx2")
# pragma GCC optimization ("Ofast")
# pragma GCC optimization ("unroll-loops")
# include <bits/stdc++.h>
/*
// ordered_set
# include <ext/pb_ds/assoc_container.hpp>
# include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
# define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update>
*/
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <pii, int> ppi;
typedef pair <int, pii> pip;
typedef pair <pii, pii> ppp;
typedef pair <ll, ll> pll;
# define A first
# define B second
# define endl '\n'
# define sep ' '
# define all(x) x.begin(), x.end()
# define kill(x) return cout << x << endl, 0
# define SZ(x) int(x.size())
# define lc id << 1
# define rc id << 1 | 1
# define InTheNameOfGod ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
ll power(ll a, ll b, ll md) {return (!b ? 1 : (b & 1 ? a * power(a * a % md, b / 2, md) % md : power(a * a % md, b / 2, md) % md));}
const int xn = 5e5 + 10;
const int xm = - 20 + 10;
const int sq = 320;
const int inf = 1e9 + 10;
const ll INF = 1e18 + 10;
const int mod = 1e9 + 7;
const int base = 257;
int n, k, a[xn], ans, sz[xn], arshad[xn];
int cnt[xn], c[xn], sum, ted;
vector <int> adj[xn];
bool mark[xn];
void preDFS(int v, int p = - 1){
sz[v] = 1;
for (int u : adj[v]){
if (u == p)
continue;
preDFS(u, v);
sz[v] += sz[u];
if (sz[u] > sz[arshad[v]])
arshad[v] = u;
}
}
void upd(int v, int f, int p){
if (c[a[v]] == cnt[a[v]])
sum -= cnt[a[v]];
c[a[v]] += f;
if (c[a[v]] == cnt[a[v]])
sum += cnt[a[v]];
for (int u : adj[v])
if (u != p)
upd(u, f, v);
}
void DFS(int v, int p = - 1){
for (int u : adj[v])
if (u != p && u != arshad[v])
DFS(u, v), upd(u, - 1, v);
if (arshad[v])
DFS(arshad[v], v);
for (int u : adj[v])
if (u != p && u != arshad[v])
upd(u, 1, v);
++ c[a[v]];
if (c[a[v]] == cnt[a[v]])
sum += c[a[v]];
if (sum == sz[v] && v != 1)
mark[v] = true, ++ ted;
}
void DFS2(int v, int p = - 1){
sz[v] = mark[v];
for (int u : adj[v])
if (u != p)
DFS2(u, v), sz[v] += sz[u];
ans += (mark[v] && (sz[v] == 1 || sz[v] == ted));
}
int main(){
InTheNameOfGod;
cin >> n >> k;
for (int i = 0; i < n - 1; ++ i){
int v, u;
cin >> v >> u;
adj[v].push_back(u);
adj[u].push_back(v);
}
for (int i = 1; i <= n; ++ i)
cin >> a[i], ++ cnt[a[i]];
preDFS(1), DFS(1), DFS2(1);
cout << (ans + 1) / 2 << endl;
return 0;
}
