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

[EX Q]: Sentence: 'a crowd of people skiing and enjoying the snow'. Find frequency of the letter 'o'
[EX A]: 5

[EX Q]: Sentence: 'a woman holds a wine glass upside down while wearing rabbit ears and staring at a bottle of wine'. Find frequency of the letter 'a'
[EX A]: 11

[EX Q]: Sentence: 'a parking meter on the sidewalk of a busy street'. Find frequency of the letter 't'
[EX A]:
4