#include "bits/stdc++.h"
using namespace std;
#define vec vector
#define all(x) (x).begin(), (x).end()
double solve(int N, int M, int K, int H, vec<int> X, vec<int> Y, vec<int> C, vec<int> S) {
using pii = pair<int,int>;
map<pii, int> edges;
vec<vec<pii>> adj(N);
for(int i = 0; i < M; i++) {
int u = X[i], v = Y[i], cost = C[i];
adj[u].emplace_back(v, cost);
adj[v].emplace_back(u, cost);
edges[{u, v}] = cost;
edges[{v, u}] = cost;
}
vec<int> dist(N, INT_MAX);
dist[0] = 0;
priority_queue<pii, vec<pii>, greater<pii>> pq;
pq.emplace(0, 0);
while(!pq.empty()) {
auto [d, u] = pq.top();
pq.pop();
if(d > dist[u]) continue;
for(auto [v, cost] : adj[u]) {
if(dist[v] > d + cost) {
dist[v] = d + cost;
pq.emplace(dist[v], v);
}
}
}
if(dist[H] == INT_MAX) return -1;
if (N == 2) {
return dist[H];
}
// Subtask O1
if (N == 3) {
int other = H == 1 ? 2 : 1;
double cost = INT_MAX;
if (edges.count({0, H})) {
cost = edges[{0, H}];
}
if (edges.count({0, other}) && edges.count({other, H})) {
if (S[other] == 0) cost = min(cost, (double)edges[{other, H}]);
if (S[other] == 1) cost = min(cost, (double)dist[H]);
if (S[other] == 2) cost = min(cost, (double)edges[{0, other}] / 2.0 + edges[{other, H}]);
}
return cost;
}
return dist[H];
}
