Safe Integer Input with Validation

Write a program with an inputInt() method that safely reads an integer with validation. The method should:
1. Read input as a string using nextLine()
2. Try to convert it to an integer using Integer.parseInt()
3. If conversion fails, print "Error! Input a whole number: " and try again
4. Return the valid integer

In main(), call inputInt() and display:

You entered: [number]

Example: If user enters "a", "a1", "1.1", then "1", output should show errors for first 3 inputs then prints the output shown in Expected Output.

⚠️ IMPORTANT - AUTO-INPUT MODE:
This question uses automated input testing. When you run your code, the input stream will AUTOMATICALLY contain: '1\n'

DO NOT wait for manual keyboard input - Scanner will read from the pre-filled buffer stream immediately. Your validation loop should use scanner.nextLine() to read input.

Think of it like Eclipse/VS Code but with the input already typed in and waiting for your Scanner to read it.