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

[EX Q]: Sentence: 'a burning wood stove has a tea pot sitting on top of it and is full of wood'. Find frequency of the letter 'a'
[EX A]: 5

[EX Q]: Sentence: 'a man riding a skateboard up the side of a ramp'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a man in a cap is sitting at a laptop'. Find frequency of the letter 'l'
[EX A]:
1