#include "swap.h"
#include <iostream>
#include <vector>
#include <queue>
#include <tuple>
#include <algorithm>
#include <cassert>
using namespace std;
int N,M;
vector<int> U,V,W,W_;
vector<tuple<int,int,int>> S = {};
struct Unionfind{
vector<int> par, siz;
//初期化
Unionfind(int n) : par(n,-1) , siz(n,1) {}
int root(int x) {
if(par[x] == -1) return x;
else return par[x] = root(par[x]);
}
bool issame(int x,int y) {
return root(x) == root(y);
}
bool unite(int x, int y){
x = root(x); y = root(y);
if(x == y) return false;
if(siz[x] < siz[y]) swap(x,y);
par[y] = x;
siz[x] += siz[y];
return true;
}
int size(int x) {
return siz[root(x)];
}
};
void init(int NN, int MM,
std::vector<int> UU, std::vector<int> VV, std::vector<int> WW) {
N = NN;
M = MM;
U = UU;
V = VV;
W = WW;
W_ = W;
for(int i=0;i<M;i++){
S.push_back({W[i],U[i],V[i]});
}
sort(S.begin(),S.end());
}
int getMinimumFuelCapacity(int X, int Y) {
vector<int> E = {};
vector<vector<int>> G(N);
bool cone = false;
Unionfind uf(N);
for(int i=0;i<M;i++){
int w,u,v;
tie(w,u,v) = S[i];
if(cone && uf.issame(u,v) && uf.issame(u,X)) return w;
uf.unite(u,v);
G[u].push_back(v);
G[v].push_back(u);
if(uf.issame(X,Y) && !cone){
cone = true;
vector<int> dist(N,1e9);
dist[X] = 0;
queue<int> q;
q.push(X);
while(!q.empty()){
int pos = q.front();
q.pop();
for(int x:G[pos]){
if(dist[x] != 1e9) continue;
dist[x] = dist[pos] + 1;
q.push(x);
continue;
}
}
int now = Y;
while(dist[now]){
E.push_back(now);
for(int x:G[now]){
if(dist[x]+1 == dist[now]){
now = x;
continue;
}
}
}
E.push_back(X);
for(int x:E){
if(G[x].size() >= 3) return w;
}
}
if(cone){
if((G[u].size() >= 3 && uf.issame(X,u)) || (G[v].size() >= 3 && uf.issame(X,v))) return w;
}
}
return -1;
}
