TASK DEFINITION: In this task, you need to count the number of times the given letter appears in the given sentence.
PROBLEM: Sentence: 'some people sitting on surfboards in the water'. Find frequency of the letter 't'

SOLUTION: 4

PROBLEM: Sentence: 'a black computer with a screen reading "press any key to begin."'. Find frequency of the letter 'a'

SOLUTION: 5

PROBLEM: Sentence: 'thw woman in glasses is riding a motorcycle'. Find frequency of the letter 'y'

SOLUTION:
1