C Language assignment and it is about character strings and string functions. I need your urgent help. It is due in 5 hours.

Create a program that prints a class roll sheet in alphabetical order. The user inputs the students' first name and last names (separately!), and presses enter on the first name when done. The program prints out the roster like this HATFIELD, HEIDI KAISER, RUSSELL LIPSHUTZ, HOWARD PENKERT, DAWN WRIGHT, ELIZABETH The input should work for 30 students and first name should be 15 characters