//1L1YA
#include<bits/stdc++.h>
using namespace std;
//#pragma GCC optimize ("O3,unrool-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
#define Pb push_back
#define F first
#define S second
#define endl '\n'
#define sep ' '
#define all(x) x.begin(),x.end()
#define al(x,n) x+1,x+n+1
#define SZ(x) ((int)x.size())
#define lc (id<<1)
#define rc (lc|1)
#define mid (l+r>>1)
#define dokme(x) cout << x << endl, exit(0)
#define sik(x) cout << x << endl;continue;
#define FastIO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define FileIO freopen("input.txt","r",stdin);freopen("output.txt","w",stdout);
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll oo=1e18;
const int mod=1e9+7;
const int inf=1e9+111;
const int N=5e5+11;
const int lg=23;
int n,k,ans,a[N],h[N],pr[N],cnt[N],par[lg][N];
vector<int> vc[N],adj[N];
set<int> st[N];
vector<pii> E;
bool mark[N];
void dfs(int v,int p=0){
for(int u: adj[v])
if(u!=p){
h[u]=h[v]+1;
par[0][u]=v;
dfs(u,v);
}
}
int jump(int v,int k){
for(int i=0;i<lg;i++)
if(k>>i & 1)
v=par[i][v];
return v;
}
int lca(int u,int v){
if(h[u]>h[v]) swap(u,v);
v=jump(v,h[v]-h[u]);
if(u==v) return v;
for(int i=lg-1;~i;i--)
if(par[i][u]!=par[i][v])
u=par[i][u],v=par[i][v];
return par[0][v];
}
void DFS(int v,int p=0){
st[v].insert(a[v]);
for(int u: adj[v])
if(u!=p){
DFS(u,v);
cnt[v]+=cnt[u];
if(SZ(st[v])<SZ(st[u])) st[v].swap(st[u]);
for(int x: st[u]) st[v].insert(x);
}
if(cnt[v]==SZ(st[v])) mark[v]=1;
}
void dFs(int v,int p=0){
for(int u: adj[v])
if(u!=p){
if(!mark[u]) pr[u]=pr[v];
dFs(u,v);
}
}
int main(){
FastIO
cin >> n >> k;
for(int i=1;i<n;i++){
int u,v;
cin >> u >> v;
adj[u].Pb(v);
adj[v].Pb(u);
E.Pb({u,v});
}
for(int i=1;i<=n;i++) cin >> a[i],vc[a[i]].Pb(i);
dfs(1);
for(int i=1;i<lg;i++)
for(int v=1;v<=n;v++)
par[i][v]=par[i-1][par[i-1][v]];
for(int i=1;i<=k;i++){
int v=vc[i][0];
for(int u: vc[i]) v=lca(u,v);
cnt[v]++;
}
DFS(1);
for(int i=1;i<=n;i++) pr[i]=i;
dFs(1);
fill(cnt,cnt+n+1,0);
for(auto [u,v]: E)
if(pr[u]!=pr[v]){
cnt[pr[u]]++;
cnt[pr[v]]++;
if(cnt[pr[u]]==1) ans++;
else if(cnt[pr[u]]==2) ans--;
if(cnt[pr[v]]==1) ans++;
else if(cnt[pr[v]]==2) ans--;
}
cout << (ans+1)/2 << endl;
return 0;
}
