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

Input: Consider Input: Sentence: 'a bed with a dog laying on it next to two laptop computers'. Find frequency of the letter 'n'

Output: 3


Input: Consider Input: Sentence: 'a herd of giraffe walking across a field'. Find frequency of the letter 'k'

Output: 1


Input: Consider Input: Sentence: 'a pizza with lots of cheese and toppings on a piece of fin foil'. Find frequency of the letter 't'


Output: 3