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 gray colored pigeon that is perched on a railing outside of a building, with other buildings in the background'. Find frequency of the letter 'e'

Output: 7


Input: Consider Input: Sentence: 'a woman stands in the surf with a surfboard'. Find frequency of the letter 'd'


Output: 2