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

Input: Consider Input: Sentence: 'three young people goofing around; one of the guys has a football, the girl has a teddy bear'. Find frequency of the letter 'd'

Output: 3


Input: Consider Input: Sentence: 'a full plate of food that includes rice and broccoli and carrots'. Find frequency of the letter 's'

Output: 2


Input: Consider Input: Sentence: 'a computer and sound equipment on a desk'. Find frequency of the letter 'm'


Output: 2