#include <bits/stdc++.h>
#include "cyberland.h"
// #include "stub.cpp"
using namespace std;
#define ff first
#define ss second
#define pii pair<int, int>
double solve(int n, int M, int K, int H, vector<int> x, vector<int> y, vector<int> c, vector<int> a) {
vector<pii> E[n];
for (int i = 0; i < M; i++) {
E[x[i]].push_back({y[i], c[i]});
E[y[i]].push_back({x[i], c[i]});
}
priority_queue<pair<double, pii>> q;
vector<vector<double>> dis(n, vector<double>(K + 1, 1e9));
q.push({0, {0, 0}}); dis[0][0] = 0;
while (!q.empty()) {
auto [d, x] = q.top(); d = -d; q.pop();
if (d != dis[x.ff][x.ss]) continue;
for (auto [i, w] : E[x.ff]) {
double nd = (!a[i] ? 0 : d + w);
if (nd < dis[i][x.ss]) {
dis[i][x.ss] = nd;
q.push({nd, {i, x.ss}});
}
if (a[i] == 2 && x.ss < K && nd < 2 * dis[i][x.ss]) {
dis[i][x.ss] = nd / 2;
q.push({nd / 2, {i, x.ss + 1}});
}
}
}
double mn = 1e9;
for (int i = 0; i <= K; i++)
mn = min(mn, dis[H][i]);
return (mn == 1e9 ? -1 : mn);
}
