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

Input: Consider Input: Sentence: 'a person is water skiing and there are birds flying around above them'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'statues of 2 zebras and 1 giraffe in a doorway'. Find frequency of the letter 'a'

Output: 6


Input: Consider Input: Sentence: 'a bunch of umbrellas that are in the sand'. Find frequency of the letter 'a'


Output: 5