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

[Q]: Sentence: 'an airplane is being towed away from the jet bridge'. Find frequency of the letter 's'
[A]: 1


[Q]: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'
[A]: 2


[Q]: Sentence: 'a bowl of soup, a metal spoon, and an orange on a wood surface'. Find frequency of the letter 'o'
[A]:
9