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 in costume talking on a cell phone'. Find frequency of the letter 'm'

Output: 2


Input: Consider Input: Sentence: 'a train sits on a railroad track as a metal awning covers it'. Find frequency of the letter 'l'

Output: 2


Input: Consider Input: Sentence: 'a large sitting room with several couches and chairs'. Find frequency of the letter 'r'


Output: 4