#include <bits/stdc++.h> using namespace std; #define all(x) x.begin(), x.end() const int mxN = 2e5 + 100; const int mxB = 21; vector<int> adj[mxN]; int st[mxN], sum[mxN], depth[mxN], dp[mxN][mxB], parent[mxN], total = 0, tin = 0; void dfs(int u, int par){ parent[u] = dp[u][0] = par, st[u] = ++tin, depth[u] = depth[par] + 1; for(int i = 1; i < mxB; ++i) dp[u][i] = dp[dp[u][i - 1]][i - 1]; for(auto it : adj[u]){ if(it ^ par) dfs(it, u); } } int kth(int u, int k){ for(int j = 0; j < mxB; ++j){ if(k & (1 << j)) u = dp[u][j]; } return u; } int lca(int u, int v){ if(depth[u] < depth[v]) swap(u, v); u = kth(u, depth[u] - depth[v]); if(u == v) return u; for(int j = mxB - 1; j >= 0; --j){ if(dp[u][j] ^ dp[v][j]){ u = dp[u][j], v = dp[v][j]; } } return dp[u][0]; } void update(int u, int x){ while(u > 0){ total += x; sum[u] += x; u = parent[u]; } } void update(int u, int v, int x){ update(u, x); update(v, x); update(lca(u, v), -x); } signed main(){ ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); int n, k, ans = 1e9; cin >> n >> k; vector<int> c[n + 1]; for(int i = 0, u, v; i < n - 1; ++i){ cin >> u >> v; adj[u].push_back(v); adj[v].push_back(u); } for(int i = 1, x; i <= n; ++i) { cin >> x; c[x].push_back(i); } dfs(1, -1); for(int i = 1; i <= k; ++i){ int cur = (int) c[i].size(); sort(all(c[i]), [&](int x, int y){ return st[x] < st[y]; }); c[i].push_back(c[i][0]); for(int j = 0; j < (int) c[i].size() - 1; ++j) update(c[i][j], c[i][j + 1], 1); ans = min(ans, total / 2 - cur); for(int j = 0; j < (int) c[i].size() - 1; ++j) update(c[i][j], c[i][j + 1], -1); } cout << ans << "\n"; return 0; }