fun main(args: Array<String>) {
//    val givenInput = ""
    val givenInput = "abc"

    fun invertName(name: String): String {
        require(name.isNotEmpty()) { "The string must not be empty" }
        val result = name.split("").reversed().joinToString("").substring(1)
        check(result.length == name.length) { "Input and output sized should not be different" }
        assert(name.first() == result.last()) { "The first letter \"${name.first()}\" of the input should be the last one of the output" }
        return result
    }

    print(invertName(givenInput))
}