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

[EX Q]: Sentence: 'four women around a man sitting in front of a cake'. Find frequency of the letter 'o'
[EX A]: 5

[EX Q]: Sentence: 'two persons standing outside a moving sub train'. Find frequency of the letter 'a'
[EX A]: 3

[EX Q]: Sentence: 'people on skis gather near the ski lift'. Find frequency of the letter 'e'
[EX A]:
5