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

Input: Consider Input: Sentence: 'a boy catching a frisbee while standing ins bunch of leaves'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'the meal is served and ready to be eaten'. Find frequency of the letter 'e'

Output: 8


Input: Consider Input: Sentence: 'an image of a plane about to land on the strip'. Find frequency of the letter 'r'


Output: 1