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

Input: Consider Input: Sentence: 'a white bathroom sink sitting next to a toilet'. Find frequency of the letter 'i'

Output: 5


Input: Consider Input: Sentence: 'a white paper plate with a slice of pizza on it'. Find frequency of the letter 'h'

Output: 2


Input: Consider Input: Sentence: 'a person is doing a trick on a skateboard'. Find frequency of the letter 'k'


Output: 2