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

Sentence: 'two young ladies that are dancing in the room together'. Find frequency of the letter 'a'
4

Sentence: 'decorated baseball cake in a clear plastic box'. Find frequency of the letter 'k'
1

Sentence: 'a man flying in the air while riding a skateboard'. Find frequency of the letter 'a'

6