I suggest you read each line of code and decide what it is for. Follow the logic, and see if it makes sense.

• In your first line, why are you splitting on whitespace? Are you expecting a whitespace-delimited list of numbers? Why?
• while(<>): I thought user-input was supposed to be terminated after the number of items specified initially. Your while loop will continue until EOF.
• In your while loop, you're also reading a list of numbers, but instead of space-delimited, they're "\n" delimited.
• last if $_ eq ''; This will never be true, because you never chomped your input.
• shift @numbers; Now you're ignoring the input where the user presumably told you how many integers he was going to enter. Shouldn't you be using that number somewhere, like as one of the conditions of your while loop?
• foreach(@sorted) { print $_; } This will place all your output on a single line, with no space separating it. ...oh, except you never chomped, so each item will be printed to its own line, probably for the wrong reason. ;)

I was going to offer a more elegant (and working) solution, but it turns out that your specification is incomplete, and partially contradicts the code you demonstrated. So until that's straightened out, I'm a little hesitant to demonstrate a solution that might be misinterpreting what you're trying to accomplish.