#include <bits/stdc++.h>
using namespace std;
const int maxn = 5e5+10;
int n, k;
int pai[maxn], peso[maxn];
int s[maxn], tot[maxn];
int in[maxn], out[maxn], val[maxn], sz[maxn], tt;
int qtdZero, qtdTot, sub[maxn];
int grau[maxn];
vector<int> grafo[maxn];
void Init(void)
{
for (int i = 1; i <= n; i++)
pai[i] = i, peso[i] = 1;
}
int Find(int x)
{
if (pai[x] == x) return x;
return pai[x] = Find(pai[x]);
}
void Join(int x, int y)
{
x = Find(x), y = Find(y);
if (x == y) return;
if (peso[x] < peso[y]) swap(x, y);
pai[y] = x, peso[x] += peso[y];
}
void dfs(int u, int p)
{
sz[u] = 1;
in[u] = ++tt, val[tt] = s[u];
for (auto v: grafo[u])
{
if (v == p) continue;
dfs(v, u);
sz[u] += sz[v];
}
out[u] = tt;
}
void solve(int u, int p, bool heavy)
{
int maior = -1, ind = -1;
for (auto v: grafo[u])
if (v != p && sz[v] > maior)
maior = sz[v], ind = v;
for (auto v: grafo[u])
if (v != p && v != ind)
solve(v, u, 0);
if (ind != -1)
solve(ind, u, 1);
--sub[s[u]];
if (sub[s[u]] == 0)
++qtdZero;
if (sub[s[u]] == tot[s[u]]-1)
--qtdTot;
for (auto v: grafo[u])
{
if (v != p && v != ind)
{
for (int i = in[v]; i <= out[v]; i++)
{
--sub[val[i]];
if (sub[val[i]] == 0)
++qtdZero;
if (sub[val[i]] == tot[val[i]]-1)
--qtdTot;
}
}
}
if (qtdZero+qtdTot < k)
Join(u, p);
if (!heavy)
{
for (int i = in[u]; i <= out[u]; i++)
{
++sub[val[i]];
if (sub[val[i]] == 1)
--qtdZero;
if (sub[val[i]] == tot[val[i]])
++qtdTot;
}
}
}
int main(void)
{
scanf("%d %d", &n, &k);
for (int i = 1; i < n; i++)
{
int u, v;
scanf("%d %d", &u, &v);
grafo[u].push_back(v);
grafo[v].push_back(u);
}
for (int i = 1; i <= n; i++)
{
scanf("%d", &s[i]);
tot[s[i]]++;
sub[s[i]]++;
}
qtdTot = k;
Init();
dfs(1, 0);
solve(1, 0, 0);
for (int i = 1; i <= n; i++)
for (auto v: grafo[i])
if (Find(v) != Find(i))
grau[Find(v)]++;
int leaf = 0;
for (int i = 1; i <= n; i++)
if (grau[i] == 1)
leaf++;
printf("%d\n", (leaf+1)/2);
}
