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

[Q]: Sentence: 'a white toilet sitting next to a toilet paper roller'. Find frequency of the letter 'o'
[A]: 4


[Q]: Sentence: 'a man holding a brown paper bag kite'. Find frequency of the letter 'b'
[A]: 2


[Q]: Sentence: 'a close-up of a man holding the strings of a kite'. Find frequency of the letter 'f'
[A]:
2