I need help with this in C#

Vowels and Consonants

Prompt the user to input a sentence. Once you have their sentence, figure out how many vowels (a, e, i, o, u) and how many consonants are in the sentence. Output the total number of consonants and vowels in the following format (2 separate lines and the format specifier should be general with 0 decimal places!)

There were 5 vowels in the sentence. There were 15 consonants in the sentence.

l337 Converter

Prompt the user to input a sentence. Once you have their sentence (Convert the sentence to all uppercase), you will convert their sentence to 'l337' (Links to an external site.). You will need to replace the letter on the left with the letter on the right, using the replace() function in the String class, from the following table:

A	@
E	3
H	|-|
S	$
T	7
U	|_|

Since we are very excited about our application, we want to make sure that every sentence ends with an exclamation mark! If it already ends with an exclamation mark, do not add another, otherwise concatenate a '!' at the end!