#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ld, ld> pdd;
#define fi first
#define se second
#define mp make_pair
#define fastIO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
const int N = (int)5e5 + 9;
int pi[N];
int fin(int x){
if(pi[x] == x)
return x;
return pi[x]=fin(pi[x]);
}
void unite(int a, int b){
a=fin(a);
b=fin(b);
if(a==b)
return;
pi[a] = b;
}
vector<int> T[N];
int dep[N];
int par[N];
void dfs(int u, int pr){
par[u] = pr;
for(auto p : T[u]){
if(p == pr) continue;
dep[p] = dep[u] + 1;
dfs(p, u);
}
}
vector<int> col[N];
void path(int a, int b){
a = fin(a);
b = fin(b);
while(a != b){
if(dep[a] < dep[b]) swap(a, b);
unite(a, par[a]);
a = fin(a);
b = fin(b);
}
}
int deg[N];
int main(){
fastIO;
int n,k;
cin >> n >> k;
int u, v;
for(int i = 2; i <= n; i ++ ){
cin >> u >> v;
T[u].push_back(v);
T[v].push_back(u);
}
dfs(1, -1);
int cl;
for(int i = 1; i <= n; i ++ ){
cin >> cl;
col[cl].push_back(i);
}
for(int i = 1; i <= n; i ++ )
pi[i] = i;
for(int i = 1; i <= k ; i ++ ){
for(auto p : col[i]){
path(col[i][0], p);
}
}
for(int i = 1; i <= n; i ++ )
for(auto p : T[i])
if(fin(i) != fin(p))
deg[fin(p)] ++ ;
int sz = 0;
for(int i = 1; i <= n; i ++ )
if(deg[i] == 1)
sz ++ ;
cout << (sz + 1) / 2;
return 0;
}
