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

Input: Consider Input: Sentence: 'two computers and a laptop set up on a desk'. Find frequency of the letter 'r'

Output: 1


Input: Consider Input: Sentence: 'a man serving himself pizza in a wooden booth'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'a man adjusting another mans suit in a building'. Find frequency of the letter 'n'


Output: 6