interface A {
    val s: String
}

interface B {
    val x: Int
}

abstract class C(open val d: Double)

class D :  A, C, B {
    open val y: Int
    override val d: Double

    constructor(y: Int, d: Double) : super(d) {
        this.y = y
        this.d = d
        this.s = "$y -> $d"
        this.x = y * y
    }

    override val s: String

    override val x: Int
}