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

Input: Consider Input: Sentence: 'a man opening up a package sitting on a couch'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a person holding onto a pink kite at the beach'. Find frequency of the letter 'n'

Output: 4


Input: Consider Input: Sentence: 'a crowd of people stand on a street'. Find frequency of the letter 'a'


Output: 3