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 log in the water with three birds perched on it'. Find frequency of the letter 'r'

Output: 4


Input: Consider Input: Sentence: 'a foggy pasture with several horses and sheep grazing'. Find frequency of the letter 't'


Output: 2