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 sitting in front of a laptop computer next to a child'. Find frequency of the letter 'e'

Output: 2


Input: Consider Input: Sentence: 'a closet with a fan, luggage and various boxes'. Find frequency of the letter 'a'

Output: 6


Input: Consider Input: Sentence: 'a stop sign with a red arrow on top of it pointing left'. Find frequency of the letter 'l'


Output: 1