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

[EX Q]: Sentence: 'a man standing on a tennis court holding a racquet'. Find frequency of the letter 's'
[EX A]: 2

[EX Q]: Sentence: 'a family sitting at a table in a restaurant looking at their phones'. Find frequency of the letter 't'
[EX A]: 8

[EX Q]: Sentence: 'two women on horses surrounded a three men one of them talking a picture'. Find frequency of the letter 'e'
[EX A]:
9