#include <bits/stdc++.h>
#include "cyberland.h"
using namespace std;
typedef long long ll;
double solve(int N, int M, int K, int H, vector<int> x, vector<int>
y, vector<int> c, vector<int> arr) {
vector<vector<pair<int,int>>> g(N);
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]});
}
priority_queue<pair<ll,ll>> pq;
vector<ll> d(N, 1e18);
d[0] = 0;
pq.push({0, 0});
for(int i = 1; i < N; i++) {
if(!arr[i]) {
d[i] = 0;
pq.push({0, i});
}
}
while(!pq.empty()) {
auto [x, v] = pq.top(); pq.pop();
x = -x;
if(d[v] < x) continue;
for(auto [u, w] : g[v]) {
if(d[u] > x + w) {
d[u] = x + w;
pq.push({-d[u], u});
}
}
}
double res = d[H];
if(res == 1e18) res = -1;
return res;
}
// int main() {
// cin.tie(0); ios_base::sync_with_stdio(0);
// // cout << fixed << setprecision(1) << solve(4, 4, 30, 3, {0, 0, 1, 2}, {1, 2, 3, 3}, {5, 4, 2, 4}, {1, 0, 2, 1}) << '\n';
// cout << fixed << setprecision(1) << solve(3, 2, 30, 2, {1, 2}, {2, 0}, {12, 4}, {1, 2, 1}) << '\n';
// }
