instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a red stop sign with street signs above it'. Find frequency of the letter 't'
answer:
5


question:
Sentence: 'two zebras feed on a plant through some wire mesh'. Find frequency of the letter 'o'
answer:
4


question:
Sentence: 'a white pizza with cheese and a class of water nearby'. Find frequency of the letter 's'
answer:

3