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: 'an old woman is holding her cat in front of a camera'. Find frequency of the letter 'r'

Output: 3


Input: Consider Input: Sentence: 'the kids are sitting at the table in the kitchen'. Find frequency of the letter 'i'


Output: 5