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

Input: Consider Input: Sentence: 'a train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'

Output: 3


Input: Consider Input: Sentence: 'a group of people are playing soccer on a beach'. Find frequency of the letter 'l'

Output: 2


Input: Consider Input: Sentence: 'a baseball player standing at home plate getting ready to bat'. Find frequency of the letter 'y'


Output: 2