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

Input: Consider Input: Sentence: 'a bunch of broken down trains sit in a yard'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a dog laying on the back of a boat in the water'. Find frequency of the letter 't'

Output: 4


Input: Consider Input: Sentence: 'a living room filled with furniture and a flat screen tv'. Find frequency of the letter 'd'


Output: 2