instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a black computer with a screen reading "press any key to begin."'. Find frequency of the letter 'a'
answer:
5

question:
Sentence: 'a plate of food, with broccoli and nuts'. Find frequency of the letter 'b'
answer:
1

question:
Sentence: 'the zebras are in the grassy field with the giraffes'. Find frequency of the letter 'i'
answer:
4