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

Input: Consider Input: Sentence: 'a dog sitting in the back of a truck flat bed'. Find frequency of the letter 'h'

Output: 1


Input: Consider Input: Sentence: 'a bathroom with a sink, counter top, and mirror is shown'. Find frequency of the letter 'i'

Output: 4


Input: Consider Input: Sentence: 'black cat laying in a silver sink squinting at the camera'. Find frequency of the letter 's'


Output: 3