//Challenge: Accepted
#include <iostream>
#include <algorithm>
#include <vector>
#include <utility>
#define ll long long
#define maxn 500005
#define pii pair<int, int>
#define ff first
#define ss second
#define io ios_base::sync_with_stdio(0);cin.tie(0);
using namespace std;
vector<int> adj[maxn], tree[maxn];
int tot;
int col[2 * maxn], prv[maxn], cnt[maxn], par[maxn], ind[maxn];
//cnt: number of nodes colored i, ind: dsu parent
int num[maxn], ord[2 * maxn], arr[2 * maxn];
//ord: euler tour array, num: ans to query, arr:previous item
bool poss[maxn];
struct BIT {
int bit[2 * maxn];
void modify(int ind, int val) {
if (ind == 0) return;
for (;ind < 2 * maxn;ind += ind & (-ind)) bit[ind] += val;
}
int query(int ind) {
int ret = 0;
for (;ind > 0;ind -= ind & (-ind)) ret += bit[ind];
return ret;
}
} bb;
struct query{
int l, r, id; //[l, r]
query() {
l = 0, r = 0, id = 0;
}
query(int a, int b, int c) {
l = a, r = b, id = c;
}
};
vector<query> que;
inline bool cmp(query a, query b) {
return a.r < b.r;
}
int cur, ti = 1;
void dfs(int n, int pa) {
ord[ti] = ord[ti + tot] = n;
int lef = ti++;
par[n] = pa;
for (int v:adj[n]) {
if (v != pa) {
dfs(v, n);
}
}
int rig = ti;
//cout << n << " " << lef << " " << rig << endl;
que.push_back(query(lef, rig - 1, n));
que.push_back(query(rig, lef + tot - 1, n));
}
int find(int a) {
return a == ind[a] ? a : ind[a] = find(ind[a]);
}
void Union(int a, int b) {
ind[find(a)] = find(b);
}
int ans = 0;
void dfs2(int n, int par) {
int chi = 0;
for (int v:tree[n]) {
if (v != par) {
dfs2(v, n);
chi++;
}
}
if (chi == 0 || (n == 1 && chi == 1)) ans++;
}
int main() {
io
int n, k;
cin >> n >> k;
tot = n;
for (int i = 0;i < n - 1;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 >> col[i];
col[i + n] = col[i];
cnt[col[i]]++;
ind[i] = i;
}
dfs(1, 0);
for (int i = 1;i <= 2 * n;i++) {
arr[i] = prv[col[ord[i]]];
//cout << arr[i] << " ";
prv[col[ord[i]]] = i;
}
//cout << endl;
sort(que.begin(), que.end(), cmp);
int id = 0;
for (int i = 1;i <= 2 * n;i++) {
bb.modify(arr[i] + 1, 1);
while (id < que.size() && que[id].r == i) {
int val = que[id].r - que[id].l + 1 - (i - bb.query(que[id].l));
//cout << que[id].l << " " << que[id].r << " " << val << " " << (i - bb.query(que[id].l)) << endl;
num[que[id].id] += val;
id++;
}
}
for (int i = 2;i <= n;i++) {
//cout << num[i] << " ";
if (num[i] > k) {
poss[i] = true;
}
}
//cout << endl;
for (int i = 1;i <= n;i++) {
if (poss[i]) Union(i, par[i]);
}
int done = 1;
for (int i = 1;i <= n;i++) {
if (par[i] != 0 && !poss[i]) {
done = 0;
int a = find(i), b = find(par[i]);
tree[a].push_back(b);
tree[b].push_back(a);
}
}
if (done) cout << 0 << "\n";
else {
dfs2(find(1), 0);
cout << (ans + 1) / 2 << "\n";
}
}
/*
5 4
1 2
2 3
3 4
3 5
1
2
1
3
4
5 4
1 2
2 3
3 4
4 5
1
2
3
4
1
2 2
1 2
1
2
*/
