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

Input: Consider Input: Sentence: 'a man swinging a bat while playing baseball'. Find frequency of the letter 'm'

Output: 1


Input: Consider Input: Sentence: 'a man opening up a package sitting on a couch'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a couple of men riding on the back of bikes'. Find frequency of the letter 'b'


Output: 2