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

Input: Consider Input: Sentence: 'two indian women in colorful garb standing barefoot with two indian men'. Find frequency of the letter 'd'

Output: 3

Input: Consider Input: Sentence: 'a photo of a toilet which is not clean'. Find frequency of the letter 'w'

Output: 1

Input: Consider Input: Sentence: 'a young girl walking on a road carrying an umbrella'. Find frequency of the letter 'l'
Output: 4