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

Input: Consider Input: Sentence: 'a small dog sits in the rear window of a car'. Find frequency of the letter 'm'

Output: 1


Input: Consider Input: Sentence: 'guy leans on truck's hood while taking pics next to parked motorcycles'. Find frequency of the letter 's'

Output: 4


Input: Consider Input: Sentence: 'a man and a woman standing out in the ocean with two "boogie boards"'. Find frequency of the letter 'd'


Output: 3