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 travels on the water next to the shore'. Find frequency of the letter 'a'
[EX A]: 5

[EX Q]: Sentence: 'the skateboarder is jumping over a huge statue of a shoe'. Find frequency of the letter 'i'
[EX A]: 2

[EX Q]: Sentence: 'a bunch of chairs sitting in a room, with a fan behind them'. Find frequency of the letter 's'
[EX A]:
2