#include <iostream>
#include <iomanip>
#include <vector>
#include <queue>
#include <algorithm>
#include <utility>

using namespace std;

struct road {
	int fr, to;
	double len, v1, v2;
};

struct pos {
	int i;
	double t;

	pos(int _i, double _t): i(_i), t(_t) {}
};

bool operator <(pos a, pos b)
{
	return a.t > b.t;
}

double t_switch;

double t_on_road(road r, double t_start)
{
	double d_switch = (t_switch - t_start) * r.v1;

	if ( d_switch>=r.len ) return r.len / r.v1;
	if ( d_switch<=0     ) return r.len / r.v2;

	return d_switch / r.v1 + (r.len - d_switch) / r.v2;
}

int main()
{
	int n, m;
	cin >> n >> m >> t_switch;

	vector<road> roads(m);
	vector<vector<road>> adj(n+1);
	for(int i=0; i<m; i++) {
		road r;
		cin >> r.fr >> r.to >> r.len >> r.v1 >> r.v2;
		roads[i] = r;
		adj[r.fr].push_back(r);
		swap(r.fr, r.to);
		adj[r.fr].push_back(r);
	}

	vector<double> dist(n+1, -1);

	priority_queue<pos> q;
	q.push(pos(1, 0));

	while ( !q.empty() ) {
		pos p = q.top(); q.pop();

		if ( dist[p.i]>=0 ) continue;
		dist[p.i] = p.t;

		for(road r : adj[p.i]) {
			pos next(r.to, p.t + t_on_road(r, p.t));
			q.push(next);
		}
	}

	cout << setprecision(15) << dist[n] << endl;

	return 0;
}