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

Input: Consider Input: Sentence: 'a knife a cutting board some bananas and a toaster'. Find frequency of the letter 'i'

Output: 2


Input: Consider Input: Sentence: 'an image of a cautionary construction sign'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'a traffic light with a red and white hazard sign sitting above it'. Find frequency of the letter 't'


Output: 7