In this task, you need to count the number of times the given letter appears in the given sentence.

Ex Input:
Sentence: 'a variety of a different type of vegetables'. Find frequency of the letter 't'

Ex Output:
4


Ex Input:
Sentence: 'a group of people are playing soccer on a beach'. Find frequency of the letter 'l'

Ex Output:
2


Ex Input:
Sentence: 'a pizza pan with a pizza covered in vegetables and cheese'. Find frequency of the letter 'i'

Ex Output:

4