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

[Q]: Sentence: 'a plane with smoke coming from the tips of both wings'. Find frequency of the letter 'c'
[A]: 1

[Q]: Sentence: 'a lady mixes some things in a blender as people look on'. Find frequency of the letter 'i'
[A]: 3

[Q]: Sentence: 'a picnic bench on the shore of a lake with mountains in the background'. Find frequency of the letter 's'
[A]:
2