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: 'man in a radio studio wearing a suit in front of a microphone'. Find frequency of the letter 't'

Output: 3


Input: Consider Input: Sentence: 'a man using a video game controller in a room'. Find frequency of the letter 'n'


Output: 4