#include <bits/stdc++.h>
using namespace std;
using ll = long long;
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]);
}
priority_queue<pair<double,ll>, vector<pair<double,ll>>, greater<>> pq;
pq.emplace(0, 0);
vector<bool> vis(N);
vector<double> dist(N, INT_MAX);
dist[0] = 0;
while(!pq.empty()) {
ll curCountry = pq.top().second;
double curScore = pq.top().first;
pq.pop();
if(vis[curCountry]) continue;
vis[curCountry] = true;
if(curCountry == H) continue;
for(pair<ll,ll> u : adj[curCountry]) {
ll newScore = curScore + u.second;
if(newScore < dist[u.first]) {
dist[u.first] = newScore;
pq.emplace(newScore, u.first);
}
}
}
double ans = 0;
if(!vis[H]) ans = -1;
else ans = dist[H];
return ans;
}
