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

Input: Consider Input: Sentence: 'silhouette of person playing frisbee with moutain and sunset'. Find frequency of the letter 'i'

Output: 5


Input: Consider Input: Sentence: 'a couple of men sitting next to each other under an umbrella'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a microwave locked inside a cabinet with a clear window'. Find frequency of the letter 'i'


Output: 6