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

[EX Q]: Sentence: 'a man flying through the air on a bicycle'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a view from a bathroom shows an open door'. Find frequency of the letter 'o'
[EX A]: 7

[EX Q]: Sentence: 'two partially nude young women are holding sandwiches'. Find frequency of the letter 'w'
[EX A]:
3