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

Input: Consider Input: Sentence: 'a photo of a toilet which is not clean'. Find frequency of the letter 'w'

Output: 1


Input: Consider Input: Sentence: 'a toilet sits in a cluttered bathroom next to a sink'. Find frequency of the letter 'a'

Output: 4


Input: Consider Input: Sentence: 'a person trying out a gadget at a table'. Find frequency of the letter 'i'


Output: 1