How to make the perfect input?

Question

Kotlin

Hello everyone, let's suppose that you need to get the number a from the console from the user and check whether this number is greater than zero?
How to make it beautiful from without bulky designs?
The above variant only checks for Integer, but skips negative numbers.

print("Введите число A: ")
    val a = readLine()?.toIntOrNull() ?: print("Вы ввели не число\n")
    print("Вы ввели число: ${a}")

This design is compliant but not restrained

val n = readLine()?.toIntOrNull()
        ?.let { a ->
            if (a > 0) {
                println("Вы ввели число: ${a}")
            } else {
                println("Введенное число отрицательное\n")
            }
        }
        ?: println("Вы ввели не число\n")

Answer 1

val a = readLine()?.toIntOrNull()?.takeIf { it > 0 }

println(if (a == null) "Вы ввели не число" else "Вы ввели число: $a" )

Answer 2

print (readLine()?.toIntOrNull()?:0>0)