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

Input: Consider Input: Sentence: 'bathroom scene with a black cat going behind the door'. Find frequency of the letter 'e'

Output: 4


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 building hiding beyond a stop sign and street sign'. Find frequency of the letter 'i'


Output: 6