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

Input: Consider Input: Sentence: 'a ready to eat pizza on a rack'. Find frequency of the letter 'r'

Output: 2


Input: Consider Input: Sentence: 'a microwave oven with a yellow note on the door'. Find frequency of the letter 'w'

Output: 3


Input: Consider Input: Sentence: 'a plate of broccoli  with bread and mushrooms with rice'. Find frequency of the letter 'o'


Output: 5