fn main() {
	let mut s = String::new();
	std::io::stdin().read_line(&mut s).ok();
	let v: Vec<i64> = s.split_whitespace().flat_map(str::parse).collect();
	let f = v[0] == v[2]
		|| v[1] == v[3]
		|| (v[0] - v[2]).abs() + (v[1] - v[3]).abs() < 4;
	println!("{}", if f { 1 } else { 2 })
}