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

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 bunch of broken down trains sit in a yard'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a girl hitting a tennis ball on a court'. Find frequency of the letter 'l'


Output: 3