#include "cyberland.h"
#include <bits/stdc++.h>
using namespace std;
#define debug(x) cerr<<#x" = "<<x<<"\n";
#define debugv(x) cerr<<#x" = [ "; for(auto v:x) cerr << v << ", "; cerr<<"]\n";
using ll=long long;
using ld=double;
const ld INF=1e18;
double solve(int N,int M,int K,int H,vector<int> x,vector<int> y,vector<int> c,vector<int> arr){
K=min(K,70); ld ans=INF;
vector<vector<ld>> A(K+1,vector<ld>(N,INF));
vector<pair<ll,ld>> g[N]; priority_queue<pair<ld,ll>> pq;
for(int i=0; i<M; i++){
g[x[i]].push_back({y[i],c[i]});
g[y[i]].push_back({x[i],c[i]});
}
pq.push({0,0}); A[0][0]=0;
for(int i=0; i<=K; i++){
for(int j=0; j<N; j++) if(A[i][j]!=INF) pq.push({A[i][j],j});
while(!pq.empty()){
auto [w,v]=pq.top(); pq.pop();
if(A[i][v]<-w || v==H) continue;
for(auto [u,w2]:g[v]){
if(arr[u]==0){
A[i][u]=0;
pq.push({0,u});
}else if(A[i][u]>-w+w2){
A[i][u]=-w+w2;
pq.push({w-w2,u});
}
if(arr[u]==2 && i!=K && A[i+1][u]>(-w+w2)/2) A[i+1][u]=(-w+w2)/2;
}
}
}
for(int i=0; i<=K; i++) ans=min(ans,A[i][H]);
if(ans==INF) return -1;
else return ans;
}
