#include <bits/stdc++.h>
using namespace std;
using ll = long long;
vector<bool> isReachable;
void dfs(ll v, vector<vector<pair<ll,ll>>>& adj, ll H) {
if(v == H) return;
for(pair<ll,ll> u : adj[v]) {
if(!isReachable[u.first]) {
isReachable[u.first] = true;
dfs(u.first, adj, H);
}
}
}
double solve(int N, int M, int K, int H, std::vector<int> x, std::vector<int>y, std::vector<int> c, std::vector<int> arr) {
vector<vector<pair<ll,ll>>> adj(N);
for (int i = 0; i < M; i++) {
adj[x[i]].emplace_back(y[i], c[i]);
adj[y[i]].emplace_back(x[i], c[i]);
}
isReachable.clear();
isReachable.resize(N);
dfs(0, adj, H);
isReachable[0] = true;
if(!isReachable[H]) return -1;
priority_queue<pair<double,ll>, vector<pair<double,ll>>, greater<>> pq;
pq.emplace(0, H);
vector<bool> vis(N);
vector<double> dist(N, 1e16);
dist[H] = 0;
while(!pq.empty()) {
ll curCountry = pq.top().second;
double curScore = pq.top().first;
pq.pop();
if(vis[curCountry]) continue;
vis[curCountry] = true;
for(pair<ll,ll> u : adj[curCountry]) {
double newScore;
newScore = curScore + u.second;
if(newScore < dist[u.first]) {
dist[u.first] = newScore;
pq.emplace(newScore, u.first);
}
}
}
double ans = dist[0];
for(int i = 0; i < arr.size(); i++) {
if(arr[i] == 0 && isReachable[i]) {
ans = min(ans, dist[i]);
}
}
return ans;
}
