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

[EX Q]: Sentence: 'a person is holding a chocolate doughnut with rainbow sprinkles'. Find frequency of the letter 's'
[EX A]: 4

[EX Q]: Sentence: 'an old woman is holding her cat in front of a camera'. Find frequency of the letter 'r'
[EX A]: 3

[EX Q]: Sentence: 'a teddy bear is looking at fishes on the computer monitor'. Find frequency of the letter 'p'
[EX A]:
1