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

Input: Consider Input: Sentence: 'a small wrinkley dog wearing a bow tie'. Find frequency of the letter 'e'

Output: 3


Input: Consider Input: Sentence: 'man in red shirt with black suitcase standing outside of building'. Find frequency of the letter 'i'

Output: 8


Input: Consider Input: Sentence: 'a snowboarder next to a tube for tricks'. Find frequency of the letter 'o'


Output: 4