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

Input: Consider Input: Sentence: 'a woman at a table checking her cell phone'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a police officer who is riding on a horse'. Find frequency of the letter 'p'

Output: 1


Input: Consider Input: Sentence: 'a cheesy pizza with two glasses of bear are shown'. Find frequency of the letter 'o'


Output: 3