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

Input: Consider Input: Sentence: 'a picture of a toilet and toilet paper in a bathroom'. Find frequency of the letter 'o'

Output: 5


Input: Consider Input: Sentence: 'a birthday cake with a number one and three candle'. Find frequency of the letter 'w'

Output: 1


Input: Consider Input: Sentence: 'many toilets lined up against a wall in a rooms'. Find frequency of the letter 'l'


Output: 4