#include <bits/stdc++.h> using namespace std; #define all(x) x.begin(), x.end() const int mxN = 2e5 + 100; vector<int> adj[mxN], col[mxN]; int sz[mxN], vis[mxN], id[mxN], vis_col[mxN], parent[mxN], n, k, ans = mxN; void dfs(int u, int par){ parent[u] = par; for(auto it : adj[u]){ if(!vis[it] && it ^ par) dfs(it, u); } } void calc_sz(int u, int par){ sz[u] = 1; for(auto it : adj[u]){ if(!vis[it] && it ^ par){ calc_sz(it, u); sz[u] += sz[it]; } } } int find_cent(int u, int par, int nby2){ for(auto it : adj[u]){ if(!vis[it] && it ^ par && sz[it] >= nby2){ return find_cent(it, u, nby2); } } return u; } void decompose(int u = 1, int par = -1){ calc_sz(u, -1); int cent = find_cent(u, -1, (sz[u] + 1) / 2); dfs(cent, -1); queue<int> q; q.push(id[cent]); vector<int> cvis(k + 1, 0); int cans = 0; while(q.size()){ auto tp = q.front(); q.pop(); if(cvis[tp]) continue; cvis[tp] = 1; cans += 1; for(auto it : col[tp]){ if(parent[it] != -1){ if(vis_col[id[parent[it]]]){ cans = mxN; break; } if(!cvis[id[parent[it]]]){ q.push(id[parent[it]]); //cvis[id[parent[it]]] = 1; } } } } ans = min(ans, cans); vis[cent] = 1, vis_col[id[cent]] = 1; for(auto it : adj[cent]){ if(!vis[it] && !vis_col[id[it]]) decompose(it, u); } } signed main(){ ios::sync_with_stdio(0); cin.tie(nullptr); cout.tie(nullptr); cin >> n >> k; 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; id[i] = x; col[x].push_back(i); } decompose(); cout << -- ans << "\n"; return 0; }