$***$CODE IN C$****$

Define an input to be valid if all of following conditions hold:

All alphabetic letters are lower case, like $$c programming!$,$

Non alphabetic letters can only be digits, white space, exclamation point, question mark, or period.

Write a program that prompts the user to enter input. The program determines if the input is a valid or invalid.

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.

Example #$1$

Enter input: spring$\_24$

invalid

Example #$2$

Enter input: $8$ little pigs!

valid

Example #$3$

Enter input: Computer science?

invalid

Example #$4$

Enter input: the obstacle is the way.

valid