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: 'man riding a skate board down the little board way'. Find frequency of the letter 'k'

Output: 1


Input: Consider Input: Sentence: 'a close up of an old air plane in a hanger on display'. Find frequency of the letter 'a'


Output: 7