let f a b c d = [(abs (a-b) < d; abs (b-c) < d; abs (c-a)< d)];;
let f2 [b1;b2;b3] = if b3 then "Yes" else (if b2 && b1 then "Yes" else "No");;
let () = Scanf.scanf "%d %d %d" f
|> f2 |> Printf.printf "%s\n"