#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 5;
int n, k, f[N], g[N], leaf, tot;
vector<int> ad[N], vt[N];
int in[N], out[N], timer, up[N][20];
void dfs0(int u, int p){
in[u] = ++timer;
for(int i = 1; i <= 18; i++) up[u][i] = up[up[u][i - 1]][i - 1];
for(auto v : ad[u]) if(v != p){
up[v][0] = u;
dfs0(v, u);
}
out[u] = timer;
}
bool anc(int u, int v){ return in[u] <= in[v] && out[v] <= out[u]; }
int LCA(int u, int v){
if(anc(u, v)) return u;
if(anc(v, u)) return v;
for(int i = 18; i >= 0; i--)
if(up[u][i] && !anc(up[u][i], v)) u = up[u][i];
return up[u][0];
}
void dfs1(int u, int p){
for(auto v : ad[u]) if(v != p){
dfs1(v, u);
f[u] += f[v];
g[u] += g[v] + (!f[v]);
}
if(!f[u]) tot += 1;
}
void dfs2(int u, int p){
for(auto v : ad[u]) if(v != p){
dfs2(v, u);
if(!f[v]) leaf += (!g[v]) + (g[v] + 1 == tot);
}
}
int32_t main(){
cin.tie(0)->sync_with_stdio(0);
// #define task "test"
// if(fopen(task ".inp", "r")){
// freopen(task ".inp", "r", stdin);
// freopen(task ".out", "w", stdout);
// }
cin >> n >> k;
for(int i = 1; i < n; i++){
int u, v; cin >> u >> v;
ad[u].push_back(v); ad[v].push_back(u);
}
for(int i = 1; i <= n; i++){
int x; cin >> x;
vt[x].push_back(i); f[i] = 1;
}
dfs0(1, -1);
for(int x = 1; x <= k; x++){
int p = vt[x][0];
for(auto i : vt[x]) p = LCA(p, i);
f[p] -= vt[x].size();
}
dfs1(1, -1);
dfs2(1, -1);
cout << (leaf + 1) / 2 << "\n";
return 0;
}
