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

Input: Consider Input: Sentence: 'a group of giraffes walk together by a hill'. Find frequency of the letter 'b'

Output: 1


Input: Consider Input: Sentence: 'a man in a sweatshirt is taking his own picture'. Find frequency of the letter 'u'

Output: 1


Input: Consider Input: Sentence: 'a bunch of trays of hot dogs and fries on laps'. Find frequency of the letter 'f'


Output: 3