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 cross country skiing in a competition'. Find frequency of the letter 's'

Output: 3


Input: Consider Input: Sentence: 'men are riding on motorcycles with a man riding in their carriers'. Find frequency of the letter 'r'

Output: 8


Input: Consider Input: Sentence: 'a wood table topped with a candle and computer'. Find frequency of the letter 'a'


Output: 5