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 with glasses adjusting his tie in a mirror'. Find frequency of the letter 's'

Output: 5


Input: Consider Input: Sentence: 'a plastic container next to a toilet on a wooden box'. Find frequency of the letter 'i'

Output: 3


Input: Consider Input: Sentence: 'a plate of vegetables, rice and fried fish'. Find frequency of the letter 'd'


Output: 2