#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}
int main() {
    fast_io();
    int n, m;
    long long x;
    cin >> n >> m >> x;
    using till = tuple<int, long long, long long>;
    vector<vector<till>> g(n);
    for (int i = 0; i < m; i++) {
        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});
    }
    const long long INF = 1e18;
    vector<pair<long long, long long>> dist(n, {INF, INF});
    vector<bool> vis(n);
    dist[0] = {0, 0};
    using tlli = tuple<long long, long long, int>;
    priority_queue<tlli, vector<tlli>, greater<tlli>> pq;
    pq.push({0, 0, 0});
    while (!pq.empty()) {
        auto [tt, cc, u] = pq.top();
        pq.pop();
        if (vis[u]) {
            continue;
        }
        vis[u] = true;
        for (auto [v, c, t] : g[u]) {
            long long nt = tt + t, nc = cc + c;
            nt += nc / x;
            nc %= x;
            if (dist[v] > make_pair(nt, nc)) {
                dist[v] = {nt, nc};
                pq.push({nt, nc, v});
            }
        }
    }
    if (!vis[n - 1]) {
        cout << -1 << endl;
    } else {
        cout << dist[n - 1].first + (dist[n - 1].second != 0) << endl;
    }
}