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

Input: Consider Input: Sentence: 'a street at night with trees and streetlights on'. Find frequency of the letter 't'

Output: 9


Input: Consider Input: Sentence: 'a small white plane sitting on top of the ocean'. Find frequency of the letter 'e'

Output: 4


Input: Consider Input: Sentence: 'a boy in glasses watches his brother play a video game'. Find frequency of the letter 'i'


Output: 3