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

Input: Consider Input: Sentence: 'a picture of two men on a motorcycle in front of a railroad track'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'two zebra stand near the wooden posts on a building'. Find frequency of the letter 't'

Output: 4


Input: Consider Input: Sentence: 'two men in a restaurant smiling while one of them is trying to tie their tie'. Find frequency of the letter 'n'


Output: 6