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

[Q]: Sentence: 'a pizza is in a box on a table outside'. Find frequency of the letter 'u'
[A]: 1


[Q]: Sentence: 'a person on a surfboard in the surf of a wave'. Find frequency of the letter 's'
[A]: 3


[Q]: Sentence: 'a plate has a dessert and two spoons on it'. Find frequency of the letter 't'
[A]:
4