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

Input: Consider Input: Sentence: 'a number of small boats on a beach near an umbrella'. Find frequency of the letter 's'

Output: 2


Input: Consider Input: Sentence: 'a couple of men standing inside of a liquor store'. Find frequency of the letter 'p'

Output: 1


Input: Consider Input: Sentence: 'a bathroom with a mirror above the sink, a towel rack and toilet'. Find frequency of the letter 't'


Output: 6