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

Sentence: 'a dilapidated bench in a park under a tree'. Find frequency of the letter 'p'
2

Sentence: 'an commercial airline airplane flies above the clouds'. Find frequency of the letter 'n'
3

Sentence: 'a person is holding a wii controller in their left hand'. Find frequency of the letter 'e'

4