// #32721

class Recursive1 {
    constructor(private readonly parent?: Recursive1) {}
    private depth: number = this.parent ? this.parent.depth + 1 : 0;
}

class Recursive2 {
    parent!: Recursive2;
    depth: number = this.parent.depth;
}

class Recursive3 {
    parent!: Recursive3;
    depth: number = this.parent.alpha;
    alpha = 0;
}