doggies: here is my code:

fun main() {
    readLine()!!.toInt()
    val doggies = readLine()!!.toCharArray().groupBy { it }.mapValues { it.value.size }
    println(if (doggies.any { it.value >= 2 }) "Yes" else "No")
}

Try with input “a” (n=1). What does it output? And what the output should be?

oh man, and you gave it to me on a silver platter the first time.... Thanks, still fun!