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

[Q]: Sentence: 'a doll with huge eyes and black hair with blunt bangs holds a red umbrella'. Find frequency of the letter 'e'
[A]: 5


[Q]: Sentence: 'a glass bowl of raw broccoli, a ceramic bowl of raw green chili peppers, and steel bowl of raw daikon'. Find frequency of the letter 'a'
[A]: 9


[Q]: Sentence: 'a man with glasses adjusting his tie in a mirror'. Find frequency of the letter 's'
[A]:
5