instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a man serving himself pizza in a wooden booth'. Find frequency of the letter 'n'
answer:
4


question:
Sentence: 'one man grabbing another at a table while laughing'. Find frequency of the letter 'n'
answer:
5


question:
Sentence: 'a woman cutting up a birthday cake at an outdoor party'. Find frequency of the letter 'a'
answer:

8