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

[Q]: Sentence: 'a photo of a toilet which is not clean'. Find frequency of the letter 'w'
[A]: 1


[Q]: Sentence: 'a man with a large grey and black beard and glasses and a tie'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'two hamburger sandwich halves with lettuce and other condiments'. Find frequency of the letter 't'
[A]:
6