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

Input: Consider Input: Sentence: 'the meal is served and ready to be eaten'. Find frequency of the letter 'e'

Output: 8


Input: Consider Input: Sentence: 'a red and white train passing a train station'. Find frequency of the letter 'a'

Output: 7


Input: Consider Input: Sentence: 'a microwave is kept with its door open'. Find frequency of the letter 'o'


Output: 4