#include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using ll = long long int;
#define INF 1e18+7

struct Edge {
  int to;
  int c;
  int t;
  Edge(int to, int c, int t) : to(to), c(c), t(t) {}
};

vector<int> dijkstra(int N, vector<vector<Edge>> &graph, int X) {
  vector<double> distance(N, INF);
  vector<int> from(N, -1);
  priority_queue<pair<double, int>,
                 vector<pair<double, int>>,
                 greater<pair<double, int>>> q;
  distance[0] = 0;
  q.push({0, 0});
  while (!q.empty()) {
    pair<double, int> p = q.top();
    q.pop();
    double path_now = p.first;
    int p_now = p.second;
    if (distance[p_now] < path_now)
      continue;
    for (Edge e : graph[p_now]) {
      double path_new = path_now + (double)e.c/X + (double)e.t;
      int p_new = e.to;
      if (path_new < distance[p_new]) {
	distance[p_new] = path_new;
	from[p_new] = p_now;
	q.push({path_new, p_new});
      }
    }
  }
  //return distance;
  return from;
}

int main() {
  int N, M, X;
  cin >> N >> M >> X;
  vector<vector<Edge>> g(N);
  rep(i, M) {
    int u, v, C, T;
    cin >> u >> v >> C >> T;
    u--; v--;
    g[u].push_back({v, C, T});
    g[v].push_back({u, C, T});
  }
  //vector<double> s = dijkstra(N, g);
  vector<int> s = dijkstra(N, g, X);
  //if (s[N-1] < INF)
  //  cout << (ll)((s[N-1]*X + (X-1))/X) << endl;
  //else
  //  cout << -1 << endl;
  ll time = 0;
  ll cost = 0;
  int d = N - 1;
  while (d != -1) {
    rep(i, (int)g[d].size()) {
      if (g[d][i].to == s[d]) {
	cost += g[d][i].c;
	time += g[d][i].t;
	break;
      }
    }
    d = s[d];
  }
  if (time == 0)
    cout << -1 << endl;
  else
    cout << time + (cost + (X-1)) / X << endl;
  return 0;
}