instruction:
In this task, you need to count the number of times the given letter appears in the given sentence.
question:
Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'
answer:
1


question:
Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'
answer:
3


question:
Sentence: 'a hummingbird flapping its wings while sitting on a branch'. Find frequency of the letter 'g'
answer:

4