This is for C please do not use array just nested loops because have not learned arrays yet

Write a program that asks three students about the grade they received in their classes then prints the GPA of each student. A student has an indefinite number of grades; they enter the sentinel when they no longer have grades. The classes have the same number of credits. The grades input by the user are (4,3,2,1,0). If the user enters an invalid grade, consider it as grade 0 In this program, it is known that there will be three students and each student has an indefinite number of grades. What's the suitable loop structure for this program? Below is a sample output. Include this output as one of your test cases Student 1 Class 1: 4 Class 2: 3 Class 3: 2 Class 4: 1 Class 5: -1 Student 2 Class 1: 3 Class 2: Student 3 Class 1:3 Class 2: 4 Class 3: Class 4:-1 Student 1 GPA: 2.50 Student 2 GPA: 3.00 Student 3 GPA: 2.33