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

Input: Consider Input: Sentence: 'a young boy holding a piece of paper on top of a table'. Find frequency of the letter 'y'

Output: 2


Input: Consider Input: Sentence: 'a group of people having dinner and drinking wine'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'a young woman with her arms around two young professional men'. Find frequency of the letter 'm'


Output: 3