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

Input: Consider Input: Sentence: 'a variety of a different type of vegetables'. Find frequency of the letter 't'

Output: 4

Input: Consider Input: Sentence: 'there is no image here to provide a caption for'. Find frequency of the letter 'o'

Output: 5

Input: Consider Input: Sentence: 'a couple zebras are standing in a flooded plain '. Find frequency of the letter 'a'
Output: 6