RequirementsName your program project$2\_$valid.c$.$Use getchar$()$ function to read in the input. Do not use scanf. Arrays are not allowed to solve this problem.The user input ends with the user pressing the enter key $($a new line character$).$Character handling library functions in ctype.h are allowed.Follow the format of the examples below.Examples $($your program must follow this format precisely$)$Example #$1$Enter input: spring$\_24$invalidExample #$2$Enter input: $8$ little pigs!validExample #$3$Enter input: Computer science?invalidExample #$4$