In this task, you need to count the number of times the given letter appears in the given sentence.

[Q]: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'
[A]: 1


[Q]: Sentence: 'two people holding their skies in a snowy resort'. Find frequency of the letter 'n'
[A]: 3


[Q]: Sentence: 'a scooter with a helmet hanging off it's handlebars'. Find frequency of the letter 'h'
[A]:
4