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

Input: Consider Input: Sentence: 'a cat sprawls out and sleeps on its back on a lounge chair with an acorn theme'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'a large group of motorcycles parked along a street'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a bed is made with brown velvet blanket and lime green pillows'. Find frequency of the letter 'b'


Output: 3