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

Input: Consider Input: Sentence: 'an area that has surrounded by a metal fence'. Find frequency of the letter 'o'

Output: 1


Input: Consider Input: Sentence: 'a doorway looking into a small bathroom with white toilet'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'a small and cluttered bathroom is decorated in shades of brown and white'. Find frequency of the letter 'r'


Output: 4