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

Input: Consider Input: Sentence: 'two men are playing a video game as another sits watching'. Find frequency of the letter 'a'

Output: 7


Input: Consider Input: Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'

Output: 4


Input: Consider Input: Sentence: 'a white bathroom with a walk in closet is shown'. Find frequency of the letter 'l'


Output: 2