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 playing baseball on a television set'. Find frequency of the letter 'l'

Output: 4


Input: Consider Input: Sentence: 'there is a sandwich with a lot of meat cut in half'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a man with a surf board walks across the beach'. Find frequency of the letter 'h'


Output: 3