#include <bits/stdc++.h>
using namespace std;
namespace std {
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0200r0.html
template <class Fun>
class y_combinator_result {
Fun fun_;
public:
template <class T>
explicit y_combinator_result(T&& fun) : fun_(std::forward<T>(fun)) {}
template <class... Args>
decltype(auto) operator()(Args&&... args) {
return fun_(std::ref(*this), std::forward<Args>(args)...);
}
};
template <class Fun>
decltype(auto) y_combinator(Fun&& fun) {
return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun));
}
}; // namespace std
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
#ifdef home
freopen("in", "r", stdin);
freopen("out", "w", stdout);
#endif
int n, k;
cin >> n >> k;
vector<vector<int>> adj(n);
for (int i = n - 1, u, v; i--;) {
cin >> u >> v, --u, --v;
adj[u].emplace_back(v);
adj[v].emplace_back(u);
}
vector<vector<int>> colour(k);
for (int i = 0, c; i < n; ++i) {
cin >> c, --c;
colour[c].emplace_back(i);
}
vector<int> par(n), dep(n);
par[0] = -1;
y_combinator([&](auto self, int u) -> void {
for (const auto& v : adj[u]) {
if (v == par[u]) continue;
par[v] = u, dep[v] = dep[u] + 1;
self(v);
}
})(0);
vector dsu(n, -1);
auto get_par = [&](int u) {
while (dsu[u] != -1) {
if (dsu[dsu[u]] != -1) dsu[u] = dsu[dsu[u]];
u = dsu[u];
}
return u;
};
for (const auto& nodes : colour) {
int u = get_par(nodes[0]), p;
for (auto v : nodes) {
for (v = get_par(v); u != v; u = p) {
if (dep[u] < dep[v]) swap(u, v);
p = get_par(par[u]);
dsu[u] = p;
}
}
}
vector<int> deg(n);
for (int u = 0; u < n; ++u) {
int pu = get_par(u);
for (const auto& v : adj[u]) {
if (v == par[u]) continue;
if (int pv = get_par(v); pu != pv)
++deg[pu], ++deg[pv];
}
}
cout << ((count(deg.begin(), deg.end(), 1) + 1) >> 1);
}
