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

Input: Consider Input: Sentence: 'there are two men sitting on a couch playing video games'. Find frequency of the letter 'v'

Output: 1


Input: Consider Input: Sentence: 'a person on a sidewalk jumping with an umbrella'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a woman and a dog laying down on the couch'. Find frequency of the letter 'n'


Output: 5