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

Input: Consider Input: Sentence: 'a crowd of fans watch soccer players from stadium seating'. Find frequency of the letter 'f'

Output: 3


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 train waits next to a passenger platform in a station'. Find frequency of the letter 'p'


Output: 2