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

Input: Consider Input: Sentence: 'a couple of girls are hanging out at a restaurant'. Find frequency of the letter 'l'

Output: 2


Input: Consider Input: Sentence: 'an orange cat sitting on the ground next to a  purse'. Find frequency of the letter 's'

Output: 2


Input: Consider Input: Sentence: 'a cat lays down inside of a drawer'. Find frequency of the letter 'f'


Output: 1