instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a ready to eat pizza on a rack'. Find frequency of the letter 'r'
answer:
2


question:
Sentence: 'the large modern train is on the train track'. Find frequency of the letter 'm'
answer:
1


question:
Sentence: 'a woman holding food in a napkin and posing for a bite'. Find frequency of the letter 'n'
answer:

7