#![allow(unused_imports)]
//use itertools::{iproduct, Itertools};
use proconio::input;
use proconio::marker::*;
use std::collections::*;

fn main() {
    use std::cmp::Reverse;
    input! {
        n:usize,
        m:usize,
        x:usize,
        uvct:[(Usize1,Usize1,usize,usize);m],
    }

    let mut g = vec![vec![]; n];
    for &(u, v, c, t) in uvct.iter() {
        g[u].push((v, c, t));
        g[v].push((u, c, t));
    }

    const INF: usize = std::usize::MAX;
    let mut pq = BinaryHeap::new();
    let mut times = vec![(INF, 0); n];
    pq.push(Reverse((0, 0, 0)));
    times[0] = (0, 0);
    while let Some(Reverse((time, rem, pos))) = pq.pop() {
        for &(nxt, c, t) in g[pos].iter() {
            let nxt_time = time + t + (rem + c) / x;
            let nxt_rem = (rem + c) % x;
            if (nxt_time, nxt_rem) < times[nxt] {
                times[nxt] = (nxt_time, nxt_rem);
                pq.push(Reverse((nxt_time, nxt_rem, nxt)));
            }
        }
    }

    if times[n - 1].0 == INF {
        println!("-1");
    } else {
        println!(
            "{}",
            times[n - 1].0 + if times[n - 1].1 == 0 { 0 } else { 1 }
        );
    }
}