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

Input: Consider Input: Sentence: 'an old boat on a beach near a large body of water'. Find frequency of the letter 'a'

Output: 8


Input: Consider Input: Sentence: 'a cat that is standing next to an open suitcase'. Find frequency of the letter 'e'

Output: 3


Input: Consider Input: Sentence: 'a table is covered with condiments in plastic containers'. Find frequency of the letter 's'


Output: 4