Goal: Learn to replace characters in strings.

Assignment: Recently, an epidemic of random capital letters has plagued our textbooks. Many phrases have random capitals in the middle of the sentence or even words!

Write a program that prompts the user to enter some text, scan the text and fix the capitalization as follows:

$$ The first letter of a sentence $($after a period$)$should be capitalized;

$$ The rest of the letters should be lowercase.

Note: Do not prompt the user with a message.