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

Input: Consider Input: Sentence: 'a person standing operating a cell phone in a room'. Find frequency of the letter 'n'

Output: 6


Input: Consider Input: Sentence: 'the counter of a doctor's office, including a laptop, cotton swabs, and tongue depressors'. Find frequency of the letter 'g'

Output: 2


Input: Consider Input: Sentence: 'a family of three standing around at a parade'. Find frequency of the letter 'f'


Output: 2