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

Input: Consider Input: Sentence: 'a guy riding a bike close to a car in the street'. Find frequency of the letter 'i'

Output: 4


Input: Consider Input: Sentence: 'a double-decker bus covered in children's illustrations driving next to a van'. Find frequency of the letter 'a'

Output: 4


Input: Consider Input: Sentence: 'a semi oval looking bathroom that is in someone's house'. Find frequency of the letter 'u'


Output: 1