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 group of people standing around a table filled with assorted electronic devices'. Find frequency of the letter 'w'

Output: 1


Input: Consider Input: Sentence: 'a toilet with an apparatus to the side of it'. Find frequency of the letter 'o'


Output: 3