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

Input: Consider Input: Sentence: 'a girl sits on a surfboard and smiles'. Find frequency of the letter 'i'

Output: 3


Input: Consider Input: Sentence: 'a large motorcycle that has a man dressed in old clothing next to it'. Find frequency of the letter 'a'

Output: 6


Input: Consider Input: Sentence: 'a cat sitting on top of a grey cloth and next to two staplers'. Find frequency of the letter 'l'


Output: 2