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

Input: Consider Input: Sentence: 'a doorway looking into a small bathroom with white toilet'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'a couple is cutting in to a cake at a wedding'. Find frequency of the letter 'd'

Output: 2


Input: Consider Input: Sentence: 'a man with headphones on is hunched over a sink while being recorded'. Find frequency of the letter 'd'


Output: 4