instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a group of tennis players on a tennis court'. Find frequency of the letter 'o'
answer:
4


question:
Sentence: 'a plane with stairs next to it sitting in a large lot'. Find frequency of the letter 'i'
answer:
6


question:
Sentence: 'a black and white cat is looking through branches'. Find frequency of the letter 'i'
answer:

3