instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'three men in military suits are sitting on a bench,'. Find frequency of the letter 'a'
answer:
3


question:
Sentence: 'a man paddle boarding by a boat dock in a city'. Find frequency of the letter 'o'
answer:
3


question:
Sentence: 'a messy kitchen counter with dirty utensils and spilled ingredients'. Find frequency of the letter 's'
answer:

6