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

[Q]: Sentence: 'a baseball themed birthday cake is on a serving tray'. Find frequency of the letter 'g'
[A]: 1


[Q]: Sentence: 'young girl playing with refrigerator magnet while kneeling on floor'. Find frequency of the letter 'n'
[A]: 6


[Q]: Sentence: 'a small dog looks at the camera while on the floor'. Find frequency of the letter 'a'
[A]:
5