#include <bits/stdc++.h>
using namespace std;
int const MAX=500005;
int color[MAX];
int n,k;
vector<int>tree[MAX];
int lcol[MAX],rcol[MAX];
int l[MAX],r[MAX];
int frunze;
struct answer{
int fii,st,dr;
};
void read(){
cin>>n>>k;
int i;
for(i=1;i<n;++i){
int u,v;
cin>>u>>v;
tree[u].push_back(v);
tree[v].push_back(u);
}
for(i=1;i<=n;++i)
cin>>color[i];
}
void minself(int& x,int val){
if(x>val)
x=val;
}
void maxself(int& x,int val){
if(x<val)
x=val;
}
void euler(int nod,int tata){
static int time=0;
l[nod]=++time;
for(auto fiu : tree[nod])
if(fiu!=tata)
euler(fiu,nod);
r[nod]=++time;
minself(lcol[color[nod]],l[nod]);
maxself(rcol[color[nod]],r[nod]);
}
void init(){
int i;
for(i=1;i<=k;++i){
lcol[i]=n+1;
rcol[i]=0;
}
}
answer dfs(int nod,int tata){
int nrf=0;
int st=n+1,dr=0;
for(auto fiu : tree[nod])
if(fiu!=tata){
answer ans=dfs(fiu,nod);
nrf+=ans.fii;
minself(st,ans.st);
maxself(dr,ans.dr);
}
minself(st,lcol[color[nod]]);
maxself(dr,rcol[color[nod]]);
if(st==l[nod] && dr==r[nod]){
if((nrf==0 && nod!=1) || (nrf==1 && nod==1))
++frunze;
return {1,n+1,0};
}
return {nrf,st,dr};
}
int main()
{
read();
init();
euler(1,0);
dfs(1,0);
cout<<(frunze+1)/2;
return 0;
}
