Problem:
Toggling Cases

Write a program which converts uppercase/lowercase letters to lowercase/uppercase for a given string.

Input

A string is given in a line.

Output

Print the converted string in a line. Note that you do not need to convert any characters other than alphabetical letters.

Constraints

The length of the input string < 1200

Sample Input

fAIR, LATER, OCCASIONALLY CLOUDY.

Sample Output

Fair, later, occasionally cloudy.

Solution in Kotlin (judge verdict: Wrong Answer)

fun main(args: Array<String>) {
    val input = readLine() ?: return
    val builder = StringBuilder()
    input.forEach {
        val newC = {
            when {
                it.isLowerCase() -> it.toUpperCase()
                it.isUpperCase() -> it.toLowerCase()
                else -> it
            }
        }
        builder.append(newC)
    }
    println(builder.toString())
}