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

Input: Consider Input: Sentence: 'a fluffy white car looking in a mirror'. Find frequency of the letter 'k'

Output: 1


Input: Consider Input: Sentence: 'a red train traveling down train tracks near a forest'. Find frequency of the letter 'f'

Output: 1


Input: Consider Input: Sentence: 'a large starcraft boat, on a lake, with a flag that reads "ski life" on it'. Find frequency of the letter 'h'


Output: 2