instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a dog laying on the back of a boat in the water'. Find frequency of the letter 't'
answer:
4


question:
Sentence: 'a man sitting on a motorcycle near two other men'. Find frequency of the letter 'r'
answer:
3


question:
Sentence: 'different photographs of phones, and women with phones'. Find frequency of the letter 'f'
answer:

3