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

[Q]: Sentence: 'a gourmet looking hamburger with fries on a dining table with some wine'. Find frequency of the letter 't'
[A]: 4


[Q]: Sentence: 'cars parked outside if a retail store'. Find frequency of the letter 'd'
[A]: 2


[Q]: Sentence: 'a brown dog standing on top of a pile of rocks'. Find frequency of the letter 'n'
[A]:
4