use proconio::{fastout, input};

#[fastout]
fn main() {
    input! {
        _h: usize, _w: usize,
        a: usize, b: usize,
        r1: usize, c1: usize,
        r2: usize, c2: usize,
        p: usize, q: usize,
    }
    let cr = a.max(r1).min(r2);
    let cc = b.max(c1).min(c2);
    let m = (cr, cc);

    let ans = dist((a, b), m) + dist(m, (p, q)) + dist((p, q), (a, b));
    println!("{}", ans);
}
fn dist(a: (usize, usize), b: (usize, usize)) -> usize {
    a.0.abs_diff(b.0) + a.1.abs_diff(b.1)
}