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

[EX Q]: Sentence: 'a person on a sidewalk jumping with an umbrella'. Find frequency of the letter 'a'
[EX A]: 5

[EX Q]: Sentence: 'there is an old stove with old pots on the burners'. Find frequency of the letter 't'
[EX A]: 5

[EX Q]: Sentence: 'the street signs say do not enter and one way'. Find frequency of the letter 'e'
[EX A]:
6