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

Sentence: 'a sailboat is floating near the rocky shore of a beach'. Find frequency of the letter 'o'
5

Sentence: 'a yellow fire hydrant in the forefront of a roadway'. Find frequency of the letter 'r'
5

Sentence: 'a bathroom with two mirrors, sink and shower stall'. Find frequency of the letter 'o'

5

