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

Input: Consider Input: Sentence: 'a teenager witting on a futon couch holding gaming controls in both hands'. Find frequency of the letter 'c'

Output: 3


Input: Consider Input: Sentence: 'a large grass pasture land with sheep grazing on grass'. Find frequency of the letter 'a'

Output: 7


Input: Consider Input: Sentence: 'several people going down a snowy street in skis'. Find frequency of the letter 'o'


Output: 4