In this task, you need to count the number of times the given letter appears in the given sentence.
--------
Question: Sentence: 'a woman is taking a sip of a drink from a glass'. Find frequency of the letter 'i'

Answer: 4


Question: Sentence: 'a white toilet sitting next to a toilet paper roller'. Find frequency of the letter 'o'

Answer: 4


Question: Sentence: 'there is a female tennis player playing in a match'. Find frequency of the letter 'a'

Answer:
6