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

Input: Consider Input: Sentence: 'apples, pears, and oranges are piled up for sale'. Find frequency of the letter 'a'

Output: 6


Input: Consider Input: Sentence: 'a dog laying on the back of a boat in the water'. Find frequency of the letter 't'

Output: 4


Input: Consider Input: Sentence: 'three trucks parked in front of a building'. Find frequency of the letter 'f'


Output: 2