instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'three elephants walk up a dirt trail from the water'. Find frequency of the letter 'l'
answer:
3


question:
Sentence: 'a woman is looking at sheep off in a field'. Find frequency of the letter 'm'
answer:
1


question:
Sentence: 'an empty street with a lot of people on bikes'. Find frequency of the letter 'i'
answer:

2