let a, b, c = Scanf.scanf " %d %d %d" @@ fun a b c -> a, b, c
let f a b c = abs (b - a) + abs (c - b)
let _ = List.fold_left min max_int [f a b c; f a c b; f b a c; f b c a; f c a b; f c b a] |> Printf.printf "%d\n"