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

Input: Consider Input: Sentence: 'a group of three dogs laying on a kitchen floor'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'a  woman standing next to a man on a motorcycle in front of a market'. Find frequency of the letter 'l'

Output: 1


Input: Consider Input: Sentence: 'a sleepy cat has it's head on the remote control'. Find frequency of the letter 'a'


Output: 4