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

Input: Consider Input: Sentence: 'person wearing all white leaned up against a wall with a yellow sign'. Find frequency of the letter 'a'

Output: 8


Input: Consider Input: Sentence: 'a metallic stove top oven inside of a wooden kitchen'. Find frequency of the letter 'v'

Output: 2


Input: Consider Input: Sentence: 'a bunch of sheep are standing in a group'. Find frequency of the letter 'h'


Output: 2