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

Input: Consider Input: Sentence: 'a crowd of people standing in front of a green train'. Find frequency of the letter 'g'

Output: 2


Input: Consider Input: Sentence: 'a man with a skateboard that is in the street'. Find frequency of the letter 'o'

Output: 1


Input: Consider Input: Sentence: 'three people are playing with their surfboards in the middle of the ocean on a beachfront'. Find frequency of the letter 't'


Output: 6