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

[EX Q]: Sentence: 'a small boat and a large boat on a river near a city'. Find frequency of the letter 'a'
[EX A]: 10

[EX Q]: Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'
[EX A]: 2

[EX Q]: Sentence: 'a bird with a long narrow beak and a craned neck'. Find frequency of the letter 'i'
[EX A]:
2