This for C please do not use arrays as we have not learned them yet

QUESTION 3 (10 points) Write a program that asks the user for integers and, for each integer, prints a number of stars that's equal to the integer. If the user enters a negative integer, the program should display an error message. The user ends the program by entering the sentinel of-1 In this program, the user has an indefinite number of integers and each iteration prints a number of stars that's equal to the read integer. What's the suitable loop structure for this program? Below is a sample output. Include this output as one of your test cases. Enter an integer: 4 Output:**** Enter an integer 10 Output: Enter an integer:-3 Invalid input! Enter an integer: 8 Output:*** Enter an integer -1