样例全过，但是 AC26，WA48

#include <bits/stdc++.h>
using namespace std;
long double n, s, t;
long double ans = 1e9;
bool vis[10];
struct node {
	long double sx, sy, ex, ey;
} a[10];
inline void dfs(int step, long double res, long double x, long double y) {
	if (step == n + 1) {
		ans = min(ans, res);
		return;
	}
	for (int i = 1; i <= n; i++) {
		if (!vis[i]) {
			vis[i] = 1;
			long double tt = sqrt((x - a[i].sx) * (x - a[i].sx) + (y - a[i].sy) * (y - a[i].sy)) / s;
			long double t2 = sqrt((x - a[i].ex) * (x - a[i].ex) + (y - a[i].ey) * (y - a[i].ey)) / s;
			long double t3 = sqrt((a[i].sx - a[i].ex) * (a[i].sx - a[i].ex) + (a[i].sy - a[i].ey) * (a[i].sy - a[i].ey)) / t;
			if (t < t2) {
				dfs(step + 1, res + tt + t3, a[i].ex, a[i].ey);
			} else {
				dfs(step + 1, res + t2 + t3, a[i].sx, a[i].sy);
			}
			vis[i] = 0;
		}
	}
}
signed main() {
	ios::sync_with_stdio(false);
	ios_base::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	cin >> n >> s >> t;
	for (int i = 1; i <= n; i++) {
		cin >> a[i].sx >> a[i].sy >> a[i].ex >>a[i].ey;
	}
	dfs(1, 0, 0, 0);
	printf("%.12Lf", ans);
	return 0;
}