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

[Q]: Sentence: 'a young boy standing in front of a counter with dougnuts'. Find frequency of the letter 'o'
[A]: 6


[Q]: Sentence: 'a dog laying on the back of a boat in the water'. Find frequency of the letter 't'
[A]: 4


[Q]: Sentence: 'two giraffe standing next to each other on a field'. Find frequency of the letter 'e'
[A]:
5