instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'an airplane is being towed away from the jet bridge'. Find frequency of the letter 's'
answer:
1


question:
Sentence: 'a row of vintage cars in a grassy field'. Find frequency of the letter 'v'
answer:
1


question:
Sentence: 'a white bird is standing at the water's edge'. Find frequency of the letter 'a'
answer:

4