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

[Q]: Sentence: 'an audience watches as a bird spreads its wings'. Find frequency of the letter 'd'
[A]: 3


[Q]: Sentence: 'two giraffes standing next to some trees'. Find frequency of the letter 'f'
[A]: 2


[Q]: Sentence: 'two trains on the same tracks that are facing each other'. Find frequency of the letter 't'
[A]:
7