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

Input: Consider Input: Sentence: 'two boys are doing skateboard jumps in the street'. Find frequency of the letter 's'

Output: 4


Input: Consider Input: Sentence: 'a giraffe sticking it's tongue out near a window'. Find frequency of the letter 'a'

Output: 4


Input: Consider Input: Sentence: 'a kitchen with hanging lights, an island with sink and bar stools, a refrigerator, small pantry door, wooden cabinets and shiny wood floor'. Find frequency of the letter 'n'


Output: 12