#include <bits/stdc++.h>
using namespace std;
void setup()
{
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
}
int n, k, a, b, c[500000], l[500000], r[500000];
vector<int> g[500000];
inline void DFS1(int node, int par)
{
if (l[c[node]] == -1)
{
l[c[node]] = a;
}
a++;
for (auto &i : g[node])
{
if (i != par)
{
DFS1(i, node);
}
}
r[c[node]] = a - 1;
}
inline pair<int, pair<int, int>> DFS2(int node, int par)
{
pair<int, pair<int ,int>> p;
int num, high = r[c[node]], low = l[c[node]], sp = a;
a++;
for (auto & i : g[node])
{
if (i != par)
{
p = DFS2(i, node);
low = min(low, p.second.first);
high = max(high, p.second.second);
num += p.first;
}
}
if (low == sp && high == a - 1)
{
if (node == 0)
{
b += (num == 1);
}
else
{
b += (num == 0);
num = 1;
}
}
return {num, {low, high}};
}
int main()
{
setup();
cin >> n >> k;
for (int i = 0; i < n - 1; ++i)
{
cin >> a >> b;
g[a - 1].push_back(b - 1);
g[b - 1].push_back(a - 1);
}
for (int i = 0; i < n; ++i)
{
cin >> c[i];
c[i]--;
l[c[i]] = -1;
}
a = b = 0;
DFS1(0, 0);
a = 0;
DFS2(0, 0);
cout << (b + 1) / 2;
return 0;
}
