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

[Q]: Sentence: 'a man that is on his cell phone'. Find frequency of the letter 's'
[A]: 2


[Q]: Sentence: 'a lady mixes some things in a blender as people look on'. Find frequency of the letter 'i'
[A]: 3


[Q]: Sentence: 'two men preparing cakes in the kitchen of a bakery'. Find frequency of the letter 'y'
[A]:
1