class Skls{
    var s :String? = null

    fun show(){
        println(s)
    }
}


fun main() {

    var a1 = Skls()
    a1.s = "Java"
    a1.show()

    var a2 = Skls()
    a2.s = "SQL"
    a2.show()

    var a3 = a1 + a2
    a3.show()
}


operator infix fun Skls.plus(a: Skls):Skls{
    var skls = Skls()
    skls.s = this.s +" "+a.s
    return skls
}