let split_on_char sep s = let r = ref [] in let j = ref (String.length s) in for i = String.length s - 1 downto 0 do if String.unsafe_get s i = sep then begin r := String.sub s (i + 1) (!j - i - 1) :: !r; j := i end done; String.sub s 0 !j :: !r;; let ousama a b c d = if ((a = c) || (b = d)) then 1 else if (abs (a - c) < 3) && (abs (b - d) < 3) then 1 else 2;; let () = let raw = read_line () |> split_on_char ' ' |> List.map int_of_string in let a = List.nth raw 0 in let b = List.nth raw 1 in let c = List.nth raw 2 in let d = List.nth raw 3 in ousama a b c d |> print_int; print_newline ();;