#include "cyberland.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ff first
#define ss second
const int mx=1e5+5;
vector<pair<int,int>> g[mx];
int used[mx];
long dis[mx];
set<int> s;
void dfs(int u,int fin,vector<int>& arr) {
used[u]=1;
if(!arr[u]) {
s.insert(u);
}
for(int i=0;i<int(g[u].size());++i){
int v=g[u][i].ff;
if(!used[v]&&v!=fin) {
dfs(v,fin,arr);
}
}
}
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<mx;++i) g[i].clear();
memset(used,0,sizeof(used));
for(int i=0;i<M;++i) {
g[x[i]].pb({y[i],c[i]});
g[y[i]].pb({x[i],c[i]});
}
dfs(0,H,arr);
memset(used,0,sizeof(used));
set<int>::iterator it;
priority_queue<pair<long,int>> pq;
for(it=s.begin();it!=s.end();++it) {
pq.push({*it,0});
}
for(int i=0;i<mx;++i) dis[i]=1e10;
dis[0]=0;
pq.push({0,0});
while(!pq.empty()) {
int u=pq.top().ss; pq.pop();
if(used[u]) continue;
used[u]=1;
for(int i=0;i<int(g[u].size());++i){
int v=g[u][i].ff,w=g[u][i].ss;
if(dis[u]+w<dis[v]) {
dis[v]=dis[u]+w;
pq.push({-dis[v],v});
}
}
}
if(dis[H]==1e10) {
return -1;
} else {
return dis[H];
}
}
