use itertools::iproduct;
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 mut ans = usize::MAX;
    for m in iproduct!(1..=h, 1..=w) {
        if !(r1 <= m.0 && m.0 <= r2 && c1 <= m.1 && m.1 <= c2) {
            continue;
        }
        ans = ans.min(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)
}