CHALLENGE ACTIVITY 4.2.2: Basic while loop with user input. Write an expression that executes the loop while the user enters a number greater than or equal to 0. Note: These activities may test code with different test values. This activity will perform three tests, with user input of 9, 5, 2, -1, then with user input of 0, -17, then with user input of -1. See "How to Use zyBooks" . Also note: If the submitted code has an infinite loop, the system will stop running the code after a few seconds, and report "Program end never reached." The system doesn't print the test case that caused the reported message.