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: 'a teddy bear is sitting on a heart shaped patio chair outside'. Find frequency of the letter 'i'
[A]: 6


[Q]: Sentence: 'a large crowd of people flying kites under a cloudy sky'. Find frequency of the letter 'u'
[A]:
2