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

Input: Consider Input: Sentence: 'a dog laying on the back of a boat in the water'. Find frequency of the letter 't'

Output: 4


Input: Consider Input: Sentence: 'a group of cows that are standing in the grass'. Find frequency of the letter 'g'

Output: 3


Input: Consider Input: Sentence: 'a gray and white farm animal is laying in the grass'. Find frequency of the letter 'l'


Output: 2