instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a dog has found a rather large stick for playing fetch'. Find frequency of the letter 't'
answer:
3


question:
Sentence: 'a closet with a fan, luggage and various boxes'. Find frequency of the letter 'a'
answer:
6


question:
Sentence: 'there is an airplane that is landing on the yard'. Find frequency of the letter 'i'
answer:

4