#![allow(unused_imports, unused_macros, dead_code)]

macro_rules! min {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| min!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = min!($($ys),*);
        if $x < t { $x } else { t }
    }}
}
macro_rules! max {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        it.next().map(|z| it.fold(z, |x, y| max!(x, y)))
    }};
    ($x:expr) => ($x);
    ($x:expr, $($ys:expr),*) => {{
        let t = max!($($ys),*);
        if $x > t { $x } else { t }
    }}
}


macro_rules! ewriteln {
    ($($args:expr),*) => { let _ = writeln!(&mut std::io::stderr(), $($args),*); };
}
macro_rules! trace {
    ($x:expr) => { ewriteln!(">>> {} = {:?}", stringify!($x), $x) };
    ($($xs:expr),*) => { trace!(($($xs),*)) }
}
macro_rules! put {
    (.. $x:expr) => {{
        let mut it = $x.iter();
        if let Some(x) = it.next() { print!("{}", x); }
        for x in it { print!(" {}", x); }
        println!("");
    }};
    ($x:expr) => { println!("{}", $x) };
    ($x:expr, $($xs:expr),*) => { print!("{} ", $x); put!($($xs),*) }
}

#[derive(PartialEq, Eq, PartialOrd, Ord, Clone, Copy)]
enum HypInt {
    NegInf, Real(i64), Inf
}
use HypInt::{Real, NegInf, Inf};
use std::ops::Add;
impl Add for HypInt {
    type Output = HypInt;
    fn add(self, rhs: HypInt) -> HypInt {
        match (self, rhs) {
            (Real(x), Real(y)) => Real(x + y),
            (Inf, _) => Inf,
            (_, Inf) => Inf,
            _ => NegInf,
        }
    }
}

fn main() {
    let mut sc = Scanner::new();
    let n: usize = sc.cin();
    let m: usize = sc.cin();
    let l: i64 = sc.cin();
    let mut cost = vec![vec![Inf; n]; n];
    {
        for i in 0..n {
            cost[i][i] = Real(0);
        }
        for _ in 0..m {
            let a: usize = sc.cin::<usize>() - 1;
            let b: usize = sc.cin::<usize>() - 1;
            let c: i64 = sc.cin();
            cost[a][b] = Real(c);
            cost[b][a] = Real(c);
        }
    }
    for k in 0..n {
        for i in 0..n {
            for j in 0..n {
                cost[i][j] = min!(cost[i][j], cost[i][k] + cost[k][j]);
            }}}

    let mut g = vec![vec![Inf; n]; n];
    for i in 0..n {
        for j in 0..n {
            if cost[i][j] <= Real(l) {
                g[i][j] = Real(1);
            }}}

    for k in 0..n {
        for i in 0..n {
            for j in 0..n {
                g[i][j] = min!(g[i][j], g[i][k] + g[k][j]);
            }}}

    let q: usize = sc.cin();
    for _ in 0.. q {
        let s = sc.cin::<usize>() - 1;
        let t = sc.cin::<usize>() - 1;
        match g[s][t] {
            Real(x) => put!(x - 1),
            _ => put!(-1)
        }
    }

}

use std::io::{self, Write};
use std::str::FromStr;
use std::collections::VecDeque;

struct Scanner { stdin: io::Stdin, buffer: VecDeque<String>, }
impl Scanner {
    fn new() -> Self { Scanner { stdin: io::stdin(), buffer: VecDeque::new() } }
    fn cin<T: FromStr>(&mut self) -> T {
        while self.buffer.len() == 0 {
            let mut line = String::new();
            let _ = self.stdin.read_line(&mut line);
            for w in line.split_whitespace() {
                self.buffer.push_back(String::from(w));
            }
        }
        self.buffer.pop_front().unwrap().parse::<T>().ok().unwrap()
    }
    fn chars(&mut self) -> Vec<char> { self.cin::<String>().chars().collect() }
    fn vec<T: FromStr>(&mut self, n: usize) -> Vec<T> { (0..n).map(|_| self.cin()).collect() }
}


Measured memory_bytes: 6652