#include <bits/stdc++.h>
#define Loop(x,l,r) for (ll x = (l); x < (ll)(r); ++x)
#define LoopR(x,l,r) for (ll x = (r)-1; x >= (ll)(l); --x)
typedef long long ll;
typedef std::pair<int, int> pii;
typedef std::pair<ll , ll > pll;
using namespace std;
const int N = 500'010;
int col[N];
int cnt_col[N];
bool is_in_sub[N];
vector<int> A[N];
int n, k;
class s2l {
private:
int cnt_unfin = 0;
map<int, int> mp;
public:
void insert(int x, int cnt=1)
{
int &val = mp[x];
cnt_unfin += val == 0;
val += cnt;
cnt_unfin -= val == cnt_col[x];
}
void merge(s2l *that)
{
if (this->mp.size() < that->mp.size()) {
this->mp.swap(that->mp);
swap(this->cnt_unfin, that->cnt_unfin);
}
for (auto [x, y] : that->mp)
this->insert(x, y);
delete(that);
}
bool has_unfin()
{
return cnt_unfin;
}
};
s2l *dfs1(int v, int p)
{
s2l *obj = new s2l;
obj->insert(col[v]);
for (int u : A[v]) {
if (u != p)
obj->merge(dfs1(u, v));
}
if (!obj->has_unfin() && p != -1) {
is_in_sub[v] = 1;
is_in_sub[p] = 1;
}
return obj;
}
bool dfs2(int v, int p)
{
for (int u : A[v]) {
if (u != p)
if (dfs2(u, v))
is_in_sub[v] = 1;
}
return is_in_sub[v];
}
int dfs3(int v, int p)
{
int nbr = 0;
int leaf = 0;
for (int u : A[v]) {
if (!is_in_sub[u])
continue;
nbr++;
if (u == p)
continue;
leaf += dfs3(u, v);
}
leaf += nbr == 1;
return leaf;
}
int main()
{
cin.tie(0) -> sync_with_stdio(false);
cin >> n >> k;
Loop (i,1,n) {
int v, u;
cin >> v >> u;
--v; --u;
A[v].push_back(u);
A[u].push_back(v);
}
Loop (i,0,n) {
int c;
cin >> c;
col[i] = c-1;
++cnt_col[c-1];
}
dfs1(0, -1); // I CAN LEAK ANYTHING!
int rt;
for (rt = 0; rt < n && !is_in_sub[rt]; ++rt);
if (rt == n) {
cout << "0\n";
return 0;
}
dfs2(rt, -1);
int leaves = dfs3(rt, -1);
cout << (leaves+1)/2 << '\n';
}
