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

[EX Q]: Sentence: 'salad and vegetables with me on top of plate'. Find frequency of the letter 'o'
[EX A]: 3

[EX Q]: Sentence: 'a group of cows that are standing in the grass'. Find frequency of the letter 'g'
[EX A]: 3

[EX Q]: Sentence: 'men playing tennis on a fenced in tennis court'. Find frequency of the letter 'u'
[EX A]:
1