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

Input: Consider Input: Sentence: 'a person riding a skate board on a city street'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'city two way street with cars lined up on both sides'. Find frequency of the letter 'h'

Output: 2


Input: Consider Input: Sentence: 'white square plate full of different kinds of food'. Find frequency of the letter 't'


Output: 3