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

Sentence: 'a dog on a couch near many pillows'. Find frequency of the letter 'p'
1

Sentence: 'baseball player reaching back as he's about to throw the ball'. Find frequency of the letter 'e'
5

Sentence: 'two chinese men competing playing the nintendo wii'. Find frequency of the letter 'p'

2

