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

Input: Consider Input: Sentence: 'a bed with a mattress that has nothing on it'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a young boy standing in front of a counter with dougnuts'. Find frequency of the letter 'o'

Output: 6


Input: Consider Input: Sentence: 'this kitchen is small and only has a refrigerator, microwave, sink, two small counters, and a sink'. Find frequency of the letter 'h'


Output: 3