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

[Q]: Sentence: 'a group of people seated in chairs together and facing the same direction, with one man holding a soccer ball in his hands'. Find frequency of the letter 'm'
[A]: 2


[Q]: Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'
[A]: 4


[Q]: Sentence: 'a cell phone with a video display on the screen'. Find frequency of the letter 'l'
[A]:
3