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

Sentence: 'a scene at night; a plane alone on a runway with lit-up city buildings on the horizon'. Find frequency of the letter 'w'
2

Sentence: 'there are two men sitting on a couch playing video games'. Find frequency of the letter 'v'
1

Sentence: 'a cat sitting on top of a refrigerator freezer'. Find frequency of the letter 'n'

2