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

Input: Consider Input: Sentence: 'a man serving himself pizza in a wooden booth'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'an elephant has taken a man's hat in its trunk'. Find frequency of the letter 'p'

Output: 1


Input: Consider Input: Sentence: 'some people with blue shirts water and a blue board'. Find frequency of the letter 't'


Output: 3