TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'

SOLUTION: 4

PROBLEM: Sentence: 'a bird in a tree looking up at branches'. Find frequency of the letter 'e'

SOLUTION: 3

PROBLEM: Sentence: 'two oranges sit on a tree with leaves surrounding them'. Find frequency of the letter 'w'

SOLUTION:
2