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

[Q]: Sentence: 'four men standing around two pizzas in a conference room'. Find frequency of the letter 't'
[A]: 2


[Q]: Sentence: 'a plane with stairs next to it sitting in a large lot'. Find frequency of the letter 'i'
[A]: 6


[Q]: Sentence: 'a train with graffiti painted over the door'. Find frequency of the letter 'v'
[A]:
1