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

Input: Consider Input: Sentence: 'a white bathroom sink sitting next to a toilet'. Find frequency of the letter 'i'

Output: 5


Input: Consider Input: Sentence: 'a few men walking through a market place'. Find frequency of the letter 'f'

Output: 1


Input: Consider Input: Sentence: 'a passenger jet that is at the terminal'. Find frequency of the letter 'e'


Output: 5