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

const int INF = 1e9;

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

int main() {
    int N, M, X;
    cin >> N >> M >> X;

    vector<vector<Edge>> graph(N);
    for (int i = 0; i < M; i++) {
        int u, v, c, t;
        cin >> u >> v >> c >> t;
        u--, v--;
        graph[u].emplace_back(v, c, t);
        graph[v].emplace_back(u, c, t);
    }

    vector<int> dist(N, INF), money(N, 0);
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    dist[0] = 0;
    pq.emplace(0, 0);

    while (!pq.empty()) {
        int cost = pq.top().first;
        int curr = pq.top().second;
        pq.pop();

        if (cost > dist[curr]) continue;

        for (Edge& e : graph[curr]) {
            int next_cost = cost + e.cost + e.time * X;
            int next_money = money[curr] + e.cost;
            if (next_cost < dist[e.to]) {
                dist[e.to] = next_cost;
                money[e.to] = next_money;
                pq.emplace(next_cost, e.to);
            } else if (next_cost == dist[e.to] && next_money < money[e.to]) {
                money[e.to] = next_money;
                pq.emplace(next_cost, e.to);
            }
        }
    }

    if (dist[N - 1] == INF) {
        cout << "-1" << endl;
    } else {
        cout << (dist[N - 1] + X - 1) / X << endl;
    }

    return 0;
}