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 serving himself pizza in a wooden booth'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'eight donuts are cooked together in oil in a metal tray'. Find frequency of the letter 'h'

Output: 2


Input: Consider Input: Sentence: 'a computer desk is against the wall of small living room'. Find frequency of the letter 'o'


Output: 4