func_code_string: #include <bits/stdc++.h>   using namespace std;   void FAST_IO(string filein =   , string fileout =   , string fileerr =   ) {     if (fopen(filein.c_str(),  r )) {       freopen(filein.c_str(),  r , stdin);       freopen(fileout.c_str(),  w , stdout);     }     cin.tie(0), cout.tie(0)->sync_with_stdio(0);   }   void Hollwo_Pelw();   signed main() {     FAST_IO( hollwo_pelw.inp ,  hollwo_pelw.out );     int testcases = 1;     for (int test = 1; test <= testcases; test++) {       Hollwo_Pelw();     }     return 0;   }   const int N = 2e5 + 5, L = 18;   struct edge {     int t, c, u, v;     edge(int _t = 0, int _c = 0, int _u = 0, int _v = 0)         : t(_t), c(_c), u(_u), v(_v) {}     bool operator<(const edge &o) const { return c != o.c ? c > o.c : t > o.t; }   };   int n, q, res_enj[N], res_tol[N], h[N];   vector<pair<int, int>> adj[N];   pair<int, int> jmp[N][L];   void pre_dfs(int u, int p = 0) {     h[u] = h[p] + 1;     for (int i = 1; i < 18; i++) {       auto [v1, w1] = jmp[u][i - 1];       auto [v2, w2] = jmp[v1][i - 1];       jmp[u][i] = {v2, max(w1, w2)};     }     for (auto [v, w] : adj[u])       if (v != p) {         jmp[v][0] = {u, w};         pre_dfs(v, u);       }   }   inline int get_toll(int u, int v) {     int res = 0;     if (h[u] < h[v]) swap(u, v);     for (int i = 17; ~i; i--)       if (h[u] - h[v] >> i & 1) {         auto [nu, wu] = jmp[u][i];         u = nu, res = max(res, wu);       }     if (u == v) return res;     for (int i = 17; ~i; i--)       if (jmp[u][i].first ^ jmp[v][i].first) {         auto [nu, wu] = jmp[u][i];         u = nu, res = max(res, wu);         auto [nv, wv] = jmp[v][i];         v = nv, res = max(res, wv);       }     return max({res, jmp[u][0].second, jmp[v][0].second});   }   int par[N], max_enj[N], max_pos[N], toll_in[N];   struct disjoint_set {     disjoint_set(int n = N) {       iota(par, par + n, 0);       iota(max_pos, max_pos + n, 0);     }     inline int find(int u) { return par[u] == u ? u : par[u] = find(par[u]); }     inline void merge(int u, int v) {       assert((u = find(u)) != (v = find(v)));       par[v] = u;       if (max_enj[u] < max_enj[v]) {         max_enj[u] = max_enj[v];         max_pos[u] = max_pos[v];         toll_in[u] = toll_in[v];       } else if (max_enj[u] == max_enj[v]) {         toll_in[u] =             max({toll_in[u], toll_in[v], get_toll(max_pos[u], max_pos[v])});       }     }   };   void Hollwo_Pelw() {     cin >> n >> q;     for (int i = 1; i <= n; i++) cin >> max_enj[i];     vector<edge> queries(n + q - 1);     for (int i = 0, u, v, c, t; i < n - 1; i++) {       cin >> u >> v >> c >> t;       adj[u].emplace_back(v, t);       adj[v].emplace_back(u, t);       queries[i] = edge(t, c, u, v);     }     for (int i = 0, u, c; i < q; i++) {       cin >> c >> u;       queries[i + n - 1] = {0, c, u, i};     }     pre_dfs(1);     sort(queries.begin(), queries.end());     disjoint_set dsu(n + 1);     for (auto [t, c, u, v] : queries) {       if (t) {         dsu.merge(u, v);       } else {         int pu = dsu.find(u);         res_enj[v] = max_enj[pu];         res_tol[v] = max(toll_in[pu], get_toll(u, max_pos[pu]));       }     }     for (int i = 0; i < q; i++) cout << res_enj[i] <<     << res_tol[i] <<   n ;   }   