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 throwing a frisbee on a field'. Find frequency of the letter 's'

Output: 1


Input: Consider Input: Sentence: 'a lady is standing near a luggage stand at the air port'. Find frequency of the letter 'a'

Output: 9


Input: Consider Input: Sentence: 'a box with a piece of meat inside of it'. Find frequency of the letter 'i'


Output: 5