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

Input: Consider Input: Sentence: 'a person is holding a chocolate doughnut with rainbow sprinkles'. Find frequency of the letter 's'

Output: 4


Input: Consider Input: Sentence: 'two people under an umbrella while walking down a sidewalk'. Find frequency of the letter 'i'

Output: 3


Input: Consider Input: Sentence: 'a living room filled with clutter and a small old fashioned tv'. Find frequency of the letter 'f'


Output: 2