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

[EX Q]: Sentence: 'a man and several white red and blue airplanes'. Find frequency of the letter 'u'
[EX A]: 1

[EX Q]: Sentence: 'a long row of tables displaying lots of fruit'. Find frequency of the letter 'o'
[EX A]: 5

[EX Q]: Sentence: 'a train with passenger cars stops at a train station'. Find frequency of the letter 'a'
[EX A]:
8