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

Input: Consider Input: Sentence: 'a young boy standing in front of a counter with dougnuts'. Find frequency of the letter 'o'

Output: 6


Input: Consider Input: Sentence: 'two giraffes standing next to some trees'. Find frequency of the letter 'f'

Output: 2


Input: Consider Input: Sentence: 'three people sitting on park bench next to tree overlooking valley'. Find frequency of the letter 'i'


Output: 3