data Bool = { True, False }
data List = { Nil, Cons Int List }

defn if c t e = {
    case c of {
        True -> { t }
        False -> { e }
    }
}

defn oddEven l e = {
    case l of {
        Nil -> { e }
        Cons x xs -> { evenOdd xs e }
    }
}

defn evenOdd l e = {
    case l of {
        Nil -> { e }
        Cons x xs -> { oddEven xs e }
    }
}

defn main = { if (oddEven (Cons 1 (Cons 2 (Cons 3 Nil))) True) (oddEven (Cons 1 (Cons 2 (Cons 3 Nil))) 1) 3 }