type Tree =
    | Leaf(Int)
    | Node(Tree, Tree)

fn sumTree(tree: Tree): Int =
    match tree {
    Leaf(n) => n,
    Node(left, right) => sumTree(left) + sumTree(right),
}

fn depth(tree: Tree): Int =
    match tree {
    Leaf(_) => 1,
    Node(left, right) => {
    let leftDepth = depth(left)
    let rightDepth = depth(right)
    1 + if leftDepth > rightDepth then leftDepth else rightDepth
},
}

let myTree = Node(Node(Leaf(1), Leaf(2)), Leaf(5))

let treeSum = sumTree(myTree)

let treeDepth = depth(myTree)

fn safeDivide(a: Int, b: Int): Option<Int> = if b == 0 then None else Some(a / b)

fn showResult(result: Option<Int>): String =
    match result {
    None => "Division by zero!",
    Some(n) => "Result: " + toString(n),
}

fn printResults(): Unit with {Console} = {
    Console.print("Tree sum: " + toString(treeSum))
    Console.print("Tree depth: " + toString(treeDepth))
    Console.print("Safe divide 10/2: " + showResult(safeDivide(10, 2)))
    Console.print("Safe divide 10/0: " + showResult(safeDivide(10, 0)))
}

let output = run printResults() with {}