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

Input: Consider Input: Sentence: 'party cakes in plastic containers, with a cake with a plastic santa claus and reindeer on top'. Find frequency of the letter 's'

Output: 6


Input: Consider Input: Sentence: 'a man flying through the air on top of a skateboard'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'two men and a woman are standing in front of mechanical device'. Find frequency of the letter 'a'


Output: 7