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

Input: Consider Input: Sentence: 'different sets of luggage in a baggage claim area'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'an airplane is being towed away from the jet bridge'. Find frequency of the letter 's'

Output: 1


Input: Consider Input: Sentence: 'a plate of food with meat, green beans, bread, carrots, and mashed potatoes'. Find frequency of the letter 'a'


Output: 9