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

Input: Consider Input: Sentence: 'a bunch of green bananas is hanging on a tree'. Find frequency of the letter 'n'

Output: 7


Input: Consider Input: Sentence: 'person wearing all white leaned up against a wall with a yellow sign'. Find frequency of the letter 'a'

Output: 8


Input: Consider Input: Sentence: 'an airplane sits on the tarmac at an airport'. Find frequency of the letter 't'


Output: 5