#include <bits/stdc++.h>
#define IO_OP std::ios::sync_with_stdio(0); std::cin.tie(0);
#define F first
#define S second
#define V vector
#define PB push_back
#define MP make_pair
#define EB emplace_back
#define ALL(v) (v).begin(), (v).end()
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
typedef V<int> vi;
string _reset = "\u001b[0m", _yellow = "\u001b[33m", _bold = "\u001b[1m";
void DBG() { cerr << "]" << _reset << endl; }
template<class H, class...T> void DBG(H h, T ...t) {
cerr << to_string(h);
if(sizeof ...(t)) cerr << ", ";
DBG(t...);
}
#ifdef CHEISSMART
#define debug(...) cerr << _yellow << _bold << "Line(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define debug(...)
#endif
const int INF = 1e9 + 7, N = 5e5 + 7;
vi G[N];
int p[N], lst[N], d[N], parent[N], deg[N];
void dfs(int u, int pa = 0) {
d[u] = d[pa] + 1;
parent[u] = pa;
for(int v:G[u]) if(v != pa)
dfs(v, u);
}
signed main()
{
IO_OP;
int n, k;
cin >> n >> k;
for(int i = 0; i < n - 1; i++) {
int a, b;
cin >> a >> b;
G[a].PB(b);
G[b].PB(a);
}
dfs(1);
iota(p + 1, p + n + 1, 1);
function<int(int)> find = [&] (int u) {
return p[u] == u ? u : p[u] = find(p[u]);
};
auto cover = [&] (int u, int v) {
while(find(u) != find(v)){
if(d[p[u]] > d[p[v]]) swap(u, v);
p[p[v]] = parent[p[v]];
}
};
for(int i = 1; i <= n; i++) {
int s;
cin >> s;
if(lst[s])
cover(lst[s], i);
lst[s] = i;
}
for(int i = 1; i <= n; i++)
for(int j:G[i]) if(find(i) != find(j))
deg[p[i]]++;
int cnt = 0;
for(int i = 1; i <= n; i++)
if(deg[i] == 1)
cnt++;
cout << (cnt + 1) / 2 << '\n';
}
