open class A {
    open val valProp: Int = -1
    open var varProp: Int = -1
    open var isProp: Int = -1
}

class B : J() {
    override val valProp: Int = super.valProp + 1
    override var varProp: Int
        set(value) {
            super.varProp = value
        }
        get() = super.varProp + 1

    override var isProp: Int
        set(value) {
            super.isProp = value
        }
        get() = super.isProp + 1
}

fun box(): String {
    val j = J()
    var a: A = j

    if (j.valProp != 123) return "fail 1"
    if (a.valProp != 123) return "fail 2"

    j.varProp = -1
    if (!j.okField) return "fail 3"
    j.okField = false

    a.varProp = -1
    if (!j.okField) return "fail 4"
    j.okField = false

    if (j.varProp != 456) return "fail 5"
    if (a.varProp != 456) return "fail 6"

    j.isProp = -1
    if (!j.okField) return "fail 7"
    j.okField = false

    a.isProp = -1
    if (!j.okField) return "fail 8"
    j.okField = false

    if (j.isProp != 789) return "fail 9"
    if (a.isProp != 789) return "fail 10"

    val b = B()
    a = b

    if (b.valProp != 124) return "fail 11"
    if (a.valProp != 124) return "fail 12"

    b.varProp = -1
    if (!b.okField) return "fail 13"
    b.okField = false

    a.varProp = -1
    if (!b.okField) return "fail 14"
    b.okField = false

    if (b.varProp != 457) return "fail 15"
    if (a.varProp != 457) return "fail 16"

    b.isProp = -1
    if (!b.okField) return "fail 17"
    b.okField = false

    a.isProp = -1
    if (!b.okField) return "fail 18"
    b.okField = false

    if (b.isProp != 790) return "fail 19"
    if (a.isProp != 790) return "fail 20"

    return "OK"
}