#[allow(unused_macros)]
macro_rules! input {
    (source = $s:expr, $($r:tt)*) => {
        let mut iter = $s.split_whitespace();
        let mut next = || { iter.next().unwrap() };
        input_inner!{next, $($r)*}
    };
    ($($r:tt)*) => {
        let stdin = std::io::stdin();
        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
        let mut next = move || -> String{
            bytes
                .by_ref()
                .map(|r|r.unwrap() as char)
                .skip_while(|c|c.is_whitespace())
                .take_while(|c|!c.is_whitespace())
                .collect()
        };
        input_inner!{next, $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! input_inner {
    ($next:expr) => {};
    ($next:expr, ) => {};

    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
        let $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };

    ($next:expr, mut $var:ident : $t:tt $($r:tt)*) => {
        let mut $var = read_value!($next, $t);
        input_inner!{$next $($r)*}
    };
}

#[allow(unused_macros)]
macro_rules! read_value {
    ($next:expr, ( $($t:tt),* )) => {
        ( $(read_value!($next, $t)),* )
    };

    ($next:expr, [ $t:tt ; $len:expr ]) => {
        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
    };

    ($next:expr, chars) => {
        read_value!($next, String).chars().collect::<Vec<char>>()
    };

    ($next:expr, usize1) => {
        read_value!($next, usize) - 1
    };

    ($next:expr, $t:ty) => {
        $next().parse::<$t>().expect("Parse error")
    };
}

#[allow(unused_macros)]
macro_rules! debug {
    ($($a:expr),*) => {
        #[cfg(debug_assertions)]
        writeln!(&mut std::io::stderr(), concat!("[DEBUG] ", $(stringify!($a), "={:?} "),*), $($a),*);
    }
}

#[allow(unused_imports)]
use std::cmp::{min, max};
#[allow(unused_imports)]
use std::io::{stdout, stdin, BufWriter, Write};

fn main() {
    let out = std::io::stdout();
    let mut out = BufWriter::new(out.lock());
    macro_rules! puts {
        ($($format:tt)*) => (write!(out,$($format)*).unwrap());
    }

    input!{
      n: usize,
      m: usize,
      l: usize,
      abcs: [(usize1, usize1, usize); m],
      q: usize,
      sts: [(usize1, usize1); q],
    }

    const INF: usize = 1 << 50;
    let mut dist = vec![vec![INF; n]; n];
    for &(a, b, c) in abcs.iter() {
        if c <= l {
            dist[a][b] = c;
            dist[b][a] = c;
        }
    }

    // ワーシャルフロイド
    for i in 0..n {
        dist[i][i] = INF;
    }
    for k in 0..n {
        for i in 0..n {
            for j in 0..n {
                if dist[i][k] + dist[k][j] < dist[i][j] {
                    dist[i][j] = dist[i][k] + dist[k][j];
                }
            }
        }
    }

    let mut dist2 = vec![vec![INF; n]; n];
    for i in 0..n {
        for j in 0..n {
            if dist[i][j] <= l {
                dist2[i][j] = 1;
            }
        }
    }
    for k in 0..n {
        for i in 0..n {
            for j in 0..n {
                if dist2[i][k] + dist2[k][j] < dist2[i][j] {
                    dist2[i][j] = dist2[i][k] + dist2[k][j];
                }
            }
        }
    }

    for (s, t) in sts {
        if dist2[s][t] >= INF {
            puts!("{}\n", -1);
        } else {
            puts!("{}\n", dist2[s][t]-1);
        }
    }
}


Measured memory_bytes: 8572