#include <bits/stdc++.h>
#define pii pair<int, int>
#define F first
#define S second
using namespace std;
const int P = 20;
int N, K, pre[500005][P], block[500005], deg[500005], split[500005], down[500005], up[500005], t, cc;
vector<int> state[500005];
vector<pii> E[500005];
pii io[500005];
bool ischild(int r, int c)
{
return io[r].F <= io[c].F && io[c].S <= io[r].S;
}
int lca(int u, int v)
{
int l = u;
for(int p = P - 1; p >= 0; p--)
if(pre[l][p] && !ischild(pre[l][p], v))
l = pre[l][p];
if(!ischild(l, v))
l = pre[l][0];
return l;
}
void dfs(int u)
{
io[u].F = ++t;
for(auto [v, i] : E[u])
if(v != pre[u][0])
{
pre[v][0] = u;
dfs(v);
}
io[u].S = t;
}
int find_edge(int u)
{
int cur = 0;
for(auto [v, i] : E[u])
if(v != pre[u][0])
{
int child = find_edge(v);
if(child == 0)
split[i] = 1;
cur += child;
}
// cerr << u << '=' << cur - down[u] + up[u] << '\n';
return cur - down[u] + up[u];
}
void color(int u, int r)
{
for(auto [v, i] : E[u])
if(v != pre[u][0])
{
if(split[i])
{
// cerr << u << ' ' << v << '\n';
deg[r]++, deg[++cc]++;
color(v, cc);
}
else
color(v, r);
}
}
signed main()
{
ios::sync_with_stdio(0);
cin.tie(0), cout.tie(0);
cin >> N >> K;
for(int i = 1; i < N; i++)
{
int A, B;
cin >> A >> B;
E[A].emplace_back(pii(B, i));
E[B].emplace_back(pii(A, i));
}
dfs(1);
for(int i = 1; i <= N; i++)
{
int S;
cin >> S;
state[S].emplace_back(i);
}
for(int p = 1; p < P; p++)
for(int i = 1; i <= N; i++)
pre[i][p] = pre[pre[i][p - 1]][p - 1];
for(int i = 1; i <= K; i++)
{
for(int j = 1; j < state[i].size(); j++)
{
int u = state[i][j - 1], v = state[i][j], l = lca(u, v);
if(l == u)
up[v]++, down[u]++;
else if(l == v)
up[u]++, down[v]++;
else
up[u]++, up[v]++, down[l] += 2;
}
}
find_edge(1);
color(1, ++cc);
int cnt = 0;
for(int i = 1; i <= N; i++)
if(deg[i] == 1)
cnt++;
cout << (cnt + 1) / 2 << '\n';
}
