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

[Q]: Sentence: 'a group of cows that are standing in the grass'. Find frequency of the letter 'g'
[A]: 3


[Q]: Sentence: 'cooked fish and green broccoli share a single white plate'. Find frequency of the letter 'c'
[A]: 3


[Q]: Sentence: 'a man in plaid shirt and tie standing by magazine rack'. Find frequency of the letter 'z'
[A]:
1