//In the name of Allah
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair < int , int > pii;
typedef pair < ll , ll > pll;
#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define Sz(x) (int)(x.size())
const int N = 5e5 + 10;
const int L = 20;
int h[N], par[N][L], sum[N], P[N], sz[N], deg[N];
vector < int > adj[N], vec[N];
void DFS(int v, int p){
par[v][0] = p;
for (int i = 1; i < L; i ++)
par[v][i] = par[par[v][i - 1]][i - 1];
for (int u : adj[v])
if (u != p)
h[u] = h[v] + 1, DFS(u, v);
}
void calDFS(int v, int p){
for (int u : adj[v])
if (u != p)
calDFS(u, v), sum[v] += sum[u];
sum[v] ++;
}
int getPar(int v, int t){
for (int i = 0; i < L; i ++)
if (t >> i & 1)
v = par[v][i];
return v;
}
int getLca(int u, int v){
if (h[v] < h[u])
swap(u, v);
v = getPar(v, h[v] - h[u]);
if (u == v)
return v;
for (int i = L - 1; i >= 0; i --)
if (par[u][i] != par[v][i])
u = par[u][i], v = par[v][i];
return par[v][0];
}
int get(int v){
return (P[v] == v ? v : P[v] = get(P[v]));
}
void merge(int u, int v){
u = get(u);
v = get(v);
if (u == v)
return ;
if (sz[v] < sz[u])
swap(u, v);
P[u] = v;
sz[v] += sz[u];
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, k;
cin >> n >> k;
for (int i = 1; i < n; i ++){
int u, v;
cin >> u >> v;
adj[u].pb(v);
adj[v].pb(u);
}
for (int i = 1; i <= n; i ++){
int c; cin >> c;
vec[c].pb(i);
}
DFS(1, 0);
for (int i = 1; i <= k; i ++){
int lca = vec[i][0];
for (int j = 1; j < Sz(vec[i]); j ++)
lca = getLca(lca, vec[i][j]);
sum[lca] -= Sz(vec[i]);
}
calDFS(1, 0);
for (int i = 0; i < N; i ++)
P[i] = i, sz[i] = 1;
for (int i = 2; i <= n; i ++)
if (sum[i] != 0)
merge(i, par[i][0]);
for (int i = 2; i <= n; i ++)
if (sum[i] == 0)
deg[get(i)] ++, deg[get(par[i][0])] ++;
int cnt = 0;
for (int i = 1; i <= n; i ++)
if (deg[i] == 1)
cnt ++;
cout << (cnt + 1) / 2;
return 0;
}
