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

Input: Consider Input: Sentence: 'group of cars on the road with the sun setting behind it'. Find frequency of the letter 'd'

Output: 2


Input: Consider Input: Sentence: 'a crowd of fans watch soccer players from stadium seating'. Find frequency of the letter 'f'

Output: 3


Input: Consider Input: Sentence: 'an apple with no stem sitting on a table near a knife'. Find frequency of the letter 'b'


Output: 1