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

Input: Consider Input: Sentence: 'girls posing of a picture one holding a tennis racket the other wearing a crown'. Find frequency of the letter 'g'

Output: 4


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 young child standing at home plate holding a baseball bat'. Find frequency of the letter 'a'


Output: 8