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

[EX Q]: Sentence: 'young boy flying kite in large field at outdoor event'. Find frequency of the letter 'y'
[EX A]: 3

[EX Q]: Sentence: 'a woman is looking at sheep off in a field'. Find frequency of the letter 'm'
[EX A]: 1

[EX Q]: Sentence: 'three men are getting off of an airplane'. Find frequency of the letter 't'
[EX A]:
3