//Make CSP great again
//Vengeance
#include <bits/stdc++.h>
#define TASK "TESTCODE"
#define Log2(x) 31 - __builtin_clz(x)
using namespace std;
const int N = 5e5, cbit = 18;
vector<int> num[N + 1], adj[N + 1];
int n, k, tin[N + 1], tout[N + 1], depth[N + 1], dp[N + 1], timer, res, cnt[N + 1], f[N + 1][cbit + 1];
void read()
{
cin >> n >> k;
for (int i = 1; i < n; ++ i)
{
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int u = 1; u <= n; ++ u)
{
int a;
cin >> a;
num[a].push_back(u);
}
}
void preDFS(int u, int p)
{
tin[u] = ++timer;
for (int v : adj[u])
{
if (v == p)
{
continue;
}
depth[v] = depth[u] + 1;
f[v][0] = u;
for (int i = 1; i <= cbit; ++ i)
{
f[v][i] = f[f[v][i - 1]][i - 1];
if (!f[v][i])
{
break;
}
}
preDFS(v, u);
}
tout[u] = timer;
}
int LCA(int u, int v)
{
if (depth[u] > depth[v])
{
swap(u, v);
}
int k = depth[v] - depth[u];
for (int i = cbit; i >= 0; -- i)
{
if ((k >> i) & 1)
{
v = f[v][i];
}
}
if (u == v)
{
return u;
}
for (int i = cbit; i >= 0; -- i)
{
if (f[u][i] != f[v][i])
{
u = f[u][i];
v = f[v][i];
}
}
return f[u][0];
}
void DFS_down(int u, int p)
{
for (int v : adj[u])
{
if (v == p)
{
continue;
}
DFS_down(v, u);
dp[u] += dp[v];
}
}
void DFS(int u, int p, int last_zero)
{
if (dp[u] == 0)
{
if (last_zero != -1)
{
++cnt[last_zero];
++cnt[u];
}
last_zero = u;
}
for (int v : adj[u])
{
if (v == p)
{
continue;
}
DFS(v, u, last_zero);
}
}
void solve()
{
preDFS(1, 0);
for (int i = 1; i <= k; ++ i)
{
sort(num[i].begin(), num[i].end(), [&](const int &x, const int &y)
{
return tin[x] < tin[y];
});
vector<int> add, tmp;
stack<int> st;
for (int j = 1; j < num[i].size(); ++ j)
{
add.push_back(LCA(num[i][j], num[i][j - 1]));
}
move(add.begin(), add.end(), back_inserter(num[i]));
sort(num[i].begin(), num[i].end(), [&](const int &x, const int &y)
{
return tin[x] < tin[y];
});
num[i].erase(unique(num[i].begin(), num[i].end()), num[i].end());
for (int u : num[i])
{
while(!st.empty() && (tin[u] < tin[st.top()] || tin[u] > tout[st.top()]))
{
st.pop();
}
if (!st.empty())
{
++dp[st.top()];
--dp[u];
}
st.push(u);
}
}
DFS_down(1, 0);
DFS(1, 0, -1);
for (int u = 1; u <= n; ++ u)
{
res += (cnt[u] == 1);
}
cout << (res + 1)/2;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
//freopen(TASK".OUT", "w", stdout);
}
int t = 1;
bool typetest = false;
if (typetest)
{
cin >> t;
}
for (int __ = 1; __ <= t; ++ __)
{
//cout << "Case #" << __ << ":" << '\n';
read();
solve();
}
}
