#include <bits/stdc++.h>
using namespace std;
const int N = 5e5 + 1;
int n,k,all,lwsep;
vector<int> adj[N];
int res[N],sz[N],am[N],now[N];
bool big[N],sep[N],warn;
int allt,fult;
int sepsub[N];
void pre(int u,int p){ sz[u] = 1; for(int v : adj[u]) if(v!=p) pre(v,u),sz[u]+=sz[v]; }
void add(int u,int p,int x)
{
if(now[res[u]]==am[res[u]]) fult--;
if(now[res[u]]==0) allt++;
now[res[u]]+=x;
if(now[res[u]]==am[res[u]]) fult++;
if(now[res[u]]==0) allt--;
for(int v : adj[u]) if(v!=p and !big[v]) add(v,u,x);
}
void dfs(int u,int p,bool k)
{
int mx = 0,bc = -1;
for(int v : adj[u]) if(v!=p) if(sz[v]>mx) mx = sz[v],bc = v;
for(int v : adj[u]) if(v!=p) if(v!=bc) dfs(v,u,0);
if(bc!=-1) dfs(bc,u,1),big[bc] = 1;
add(u,p,1);
sep[u] = (allt==fult);
if(sep[u] and u>1) all++;
if(bc!=-1) big[bc] = 0;
if(!k) add(u,p,-1);
}
void pres(int u,int p)
{
sepsub[u] = sep[u];
for(int v : adj[u]) if(v!=p) pres(v,u),sepsub[u]+=sepsub[v];
if(sepsub[u]==all and sep[u]) warn = true;
if(sepsub[u]==1 and sep[u] and u!=1) lwsep++;
}
int main()
{
ios_base::sync_with_stdio(0); cin.tie(0);
cin >> n >> k;
for(int i = 1;i < n;i++)
{
int a,b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
for(int i = 1;i <= n;i++) cin >> res[i],am[res[i]]++;
pre(1,0);
dfs(1,0,1);
pres(1,0);
if(!warn) cout << (lwsep+1)/2;
else if(lwsep%2==1) cout << (lwsep+1)/2;
else cout << lwsep/2+1;
}
