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

Input: Consider Input: Sentence: 'a black cat laying down on a bed'. Find frequency of the letter 'y'

Output: 1


Input: Consider Input: Sentence: 'red chair next to side table with lamp in residential home'. Find frequency of the letter 'm'

Output: 2


Input: Consider Input: Sentence: 'a man walking in front of a cinder block building near a stop sign'. Find frequency of the letter 'i'


Output: 6