String division using operator overloading in Kotlin, please help me to complete this code. No change can be made in main function.
Find common from both string like a=aabcc b=abdec answer=abc (unique common characters)
fun main(args: Array<String>)
{
val a:String = readLine()!!
val b:String = readLine()!!
val result = a/b
println(result)
}