#include <bits/stdc++.h>
using namespace std;
const int N = 500005;
vector<int> vec[N], stat[N];
int lift[20][N], marte[N], adanc[N], fin[N];
int p1[N], p2[N], pp1 = 0, pp2 = 0;
vector<int> newVec[N];
void dfs(int nod, int papa)
{
p1[nod] = ++pp1;
adanc[nod] = 1 + adanc[papa];
for (auto i : vec[nod])
if (i != papa)
dfs(i, nod);
lift[0][nod] = papa;
p2[nod] = ++pp2;
}
void dfs3(int nod, int papa)
{
if (marte[nod] == 0)
fin[nod] = nod;
else
fin[nod] = fin[papa];
for (auto i : vec[nod])
if (i != papa)
{
dfs3(i, nod);
if (marte[i] == 0)
newVec[i].push_back(fin[nod]),
newVec[fin[nod]].push_back(i);
}
}
int lca(int x, int y)
{
if (adanc[x] < adanc[y])
swap(x, y);
for (int pas = 19; pas >= 0; pas --)
if (adanc[lift[pas][x]] >= adanc[y])
x = lift[pas][x];
if (x == y)
return x;
for (int pas = 19; pas >= 0; pas --)
if (lift[pas][x] != lift[pas][y])
x = lift[pas][x], y = lift[pas][y];
return lift[0][x];
}
void dfs2(int nod, int papa)
{
for (auto i : vec[nod])
if (i != papa)
dfs2(i, nod),
marte[nod] += marte[i];
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n, k;
cin >> n >> k;
for (int i = 1; i < n; i ++)
{
int a, b;
cin >> a >> b;
vec[a].push_back(b);
vec[b].push_back(a);
}
dfs(1, 0);
for (int i = 1; i < 20; i ++)
for (int j = 1; j <= n; j ++)
lift[i][j] = lift[i - 1][lift[i - 1][j]];
for (int i = 1; i <= n; i ++)
{
int s;
cin >> s;
stat[s].push_back(i);
}
for (int i = 1; i <= k; i ++)
{
int minn = stat[i][0];
for (auto j : stat[i])
if (p1[j] < p1[minn])
minn = j;
int maxx = stat[i][0];
for (auto j : stat[i])
if (p2[j] > p2[maxx])
maxx = j;
for (auto j : stat[i])
{
int x = lca(j, minn);
marte[j] ++;
marte[minn] ++;
marte[x] -= 2;
int y = lca(j, maxx);
marte[j] ++;
marte[maxx] ++;
marte[y] -= 2;
}
}
dfs2(1, 0);
dfs3(1, 0);
int nrFrunze = 0;
for (int i = 1; i <= n; i ++)
if (newVec[i].size() == 1)
nrFrunze ++;
cout << (nrFrunze + 1) / 2 << '\n';
}
