type 'a bin_tree =
    | Red of 'a bin_tree * 'a * 'a bin_tree
    | Blue of 'a bin_tree * 'a * 'a bin_tree
    | Nil

let more_blue tree =
    let rec aux sums = function
        | Blue (l, _, r) -> qor sums (1, 0) (aux sums l) (aux sums r)
        | Red (l, _, r) -> qor sums (0, 1) (aux sums l) (aux sums r)
        | Nil -> sums
    and qor (a, b) (c, d) (e, f) (g, h) = (a + c + e + g, b + d + f + h) in
    let blues, reds = aux (0, 0) tree in
    blues > reds

let rbt = Red (Blue (Blue(Nil, 4, Red (Nil, 11, Nil)), 1, Nil), 8, Red (Nil, 4, Blue(Nil, 7, Blue (Nil, 4, Nil))))

let () = more_blue rbt |> string_of_bool |> print_endline