My switch solution not passing hidden test

Question

I had written the solution, but it not passed hidden test. I've checked the solution but it was the same with my code! I am afraid I can't move forward because of this bug. Lesson 14.2 , Go
The code:
package main

import "fmt"

func main() {
var f int
fmt.Scanln(&f)
//your code goes here
switch {
case f < 0:
fmt.Println("Wrong input")
case f < 20:
fmt.Println("Infrasound")
case f > 20000:
fmt.Println("Ultrasound")
default:
fmt.Println("Audible")
}

}

Answer 1

case f <= 20000:
fmt.Println("Audible")
default:
fmt.Println("Ultrasound")

Answer 2

Wrong input --->>> Wrong Input