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

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 small white plane sitting on top of the ocean'. Find frequency of the letter 'e'

Output: 4


Input: Consider Input: Sentence: 'ducks of a feather do flock together on calm waters'. Find frequency of the letter 'o'


Output: 5