#include <bits/stdc++.h>
#define gibon ios::sync_with_stdio(false); cin.tie(0);
#define bp __builtin_popcount
#define fir first
#define sec second
#define pii pair<int, int>
#define pll pair<ll, ll>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
typedef long long ll;
using namespace std;
int dx[4]={0, 1, 0, -1}, dy[4]={1, 0, -1 , 0};
const int mxN=502000;
const int mxM=104;
const int mxK=1000000;
const ll MOD=1000000007;
const ll INF=100000000000001;
int N, K;
vector <int> v[mxN];
vector <pii> E;
vector <int> grp[mxN];
int par[mxN][20], dep[mxN];
int S[mxN];
int root[mxN]; ///lca of all node
int uf[mxN];
int deg[mxN];
int ans;
void dfs(int now, int pre)
{
for(int nxt : v[now])
{
if(nxt==pre) continue;
par[nxt][0]=now;
dep[nxt]=dep[now]+1;
dfs(nxt, now);
}
}
int findpar(int a)
{
if(uf[a]==a) return a;
return uf[a]=findpar(uf[a]);
}
int lca(int a, int b)
{
if(dep[a]<dep[b]) return lca(b, a);
for(int i=19;i>=0;i--)
{
if(dep[a]>=dep[b]+(1<<i))
{
a=par[a][i];
}
}
if(a==b) return a;
for(int i=19;i>=0;i--)
{
if(par[a][i]!=par[b][i]) a=par[a][i], b=par[b][i];
}
return par[a][0];
}
int main()
{
gibon
cin >> N >> K;
for(int i=1;i<=N;i++) uf[i]=i;
for(int i=1;i<N;i++)
{
int a, b; cin >> a >> b;
v[a].push_back(b); v[b].push_back(a);
E.push_back({a, b});
}
dfs(1, -1);
for(int i=1;i<=19;i++) for(int j=1;j<=N;j++) par[j][i]=par[par[j][i-1]][i-1];
for(int i=1;i<=N;i++) cin >> S[i];
for(int i=1;i<=N;i++) grp[S[i]].push_back(i);
for(int i=1;i<=K;i++)
{
for(int ele : grp[i])
{
if(!root[i])
{
root[i]=ele; continue;
}
root[i]=lca(root[i], ele);
}
}
for(int i=1;i<=K;i++)
{
for(int ele : grp[i])
{
int now=ele;
while(findpar(now)!=findpar(root[i]))
{
now=findpar(now);
uf[now]=par[now][0];
now=par[now][0];
}
}
}
for(pii ele : E)
{
int a=findpar(ele.fir), b=findpar(ele.sec);
if(a==b) continue;
deg[a]++; deg[b]++;
}
for(int i=1;i<=N;i++)
{
if(deg[i]==1) ans++;
}
cout << (ans+1)/2;
}
