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

Input: Consider Input: Sentence: 'a surfer wipes out on a huge wave'. Find frequency of the letter 'a'

Output: 3


Input: Consider Input: Sentence: 'a bathroom with a sink, counter top, and mirror is shown'. Find frequency of the letter 'i'

Output: 4


Input: Consider Input: Sentence: 'a tennis player holding a racket on a white background'. Find frequency of the letter 'n'


Output: 5