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

[Q]: Sentence: 'a row of vintage cars in a grassy field'. Find frequency of the letter 'v'
[A]: 1


[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 camera and flash setup to take a pic of the inside of a oven'. Find frequency of the letter 'e'
[A]:
6