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 picture of two computers on a table'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'a group of three cats laying on top of a flowery couch'. Find frequency of the letter 't'


Output: 3