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

Input: Consider Input: Sentence: 'a herd of horses standing next to each other on a field'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'a little boy standing near a couch and a table'. Find frequency of the letter 'i'

Output: 2


Input: Consider Input: Sentence: 'lady playing racket ball on a green court, with blue wall'. Find frequency of the letter 'l'


Output: 7