Write a program that prompts a user for three characters. The user input may be duplicate. The program must validate the user input and re-prompt until a valid input is entered. The program compares those three characters and prints the largest and the smallest characters on screen.

Example 1: Input 1: C Input 2: B Input 3: A Output: C is the largest and A is the smallest.

Example 2: Input 1: A Input 2: B Input 3: a Output: a is the largest and A is the smallest.

Example 3: Input 1: S Input 2: 1 Please try again! Input 2: 500 Please try again! Input 2: M Input 3: 3 Please try again! Input 2: C Output: S is the largest and C is the smallest.

write this in C++