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

[EX Q]: Sentence: 'a plane with stairs next to it sitting in a large lot'. Find frequency of the letter 'i'
[EX A]: 6

[EX Q]: Sentence: 'a woman with short, brown hair is looking into a circular mirror and holding a camera up to her cheek'. Find frequency of the letter 'e'
[EX A]: 4

[EX Q]: Sentence: 'a dead dandelion sits in a shiny vase'. Find frequency of the letter 's'
[EX A]:
4