#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
#define all(a) (a).begin(), (a).end()
#define sz(a) (int)(a).size()
#define pb push_back
#define ll long long
#define ui uint64_t
#define ar array
#define us unordered_set
#define cont(set, element) ((set).find(element) != (set).end())
/********* DEBUG *********/
template <typename T>
void outvec(const vector<T>& Z, int hi = INT_MAX) {
int count = 0;
for (const T& x : Z) {
if (count >= hi) break;
cout << x << ' ';
count++;
}
cout << "\n";
}
// overloaded function for raw arrays
template <typename T, size_t N>
void outvec(const T (&arr)[N], int hi = INT_MAX) {
int count = 0;
for (size_t i = 0; i < N; ++i) {
if (count >= hi) break;
cout << arr[i] << ' ';
count++;
}
cout << "\n";
}
/********* DEBUG *********/
const ll inf = 1e18;
const int MOD = 1e9+7;
const int MOD2 = 998244353;
const int mxN = 200005;
// Subtask arr ∈ {0,1}
// DSU, find all possible starting places
// Push all starting nodes to Djikstra
int parent[100005];
int _find(int x){
if (parent[x] != x)
parent[x] = _find(parent[x]);
return parent[x];
}
void _uni(int x, int y){
x = _find(x);
y = _find(y);
parent[x] = y;
}
double solve(int N, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> arr) {
for (int i = 0; i < N; i++){
parent[i] = i;
}
// node, cost
vector<vector<pair<int,int>>> adj(N);
unordered_set<int> starts = {0};
for (int i = 0; i < M; i++){
adj[x[i]].pb({y[i], c[i]});
adj[y[i]].pb({x[i], c[i]});
if (x[i] != H && y[i] != H){
_uni(x[i], y[i]);
}
}
// cost, node
vector<bool> visited(N, false);
priority_queue<pair<int,int>, vector<pair<int,int>>, greater<pair<int,int>>> minheap;
minheap.push({0, 0});
for (int i = 1; i < N; i++){
if (arr[i] == 0 && _find(i) == _find(0)){
minheap.push({0, i});
}
}
int cl = 0;
while (minheap.size()){
pair<int,int> x = minheap.top(); minheap.pop();
int cst = x.first;
int nd = x.second;
visited[nd] = true;
if (nd == H){
return cst;
}
for (auto &z : adj[nd]){
if (visited[z.first])
continue;
minheap.push({cst+z.second, z.first});
}
}
return -1;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout << solve(4, 4, 30, 3, {0, 0, 1, 2}, {1, 2, 3, 3}, {5, 4, 2, 4}, {1, 1, 1, 1});
}
