fun make (n) =
    if (n =? 0) then { Leaf } else { Node (make (n - 1), make (n - 1)) }

fun count (accu, t) =
    match (t) {
    | Leaf -> 1 + accu
    | Node (l, r) -> count (count (accu, l), r)
    }

let test =
    for i from (0) to (14) {
        print_int (count (0, make (i)));
        print_string ("\n")
    }