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

Sentence: 'a white bowl filled with peeled orange slices'. Find frequency of the letter 's'
2

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

Sentence: 'a guy surfs a wave with his surfboard'. Find frequency of the letter 's'

4