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

Input: Consider Input: Sentence: 'a woman sitting in front of a giant slice of cheese pizza'. Find frequency of the letter 'e'

Output: 4


Input: Consider Input: Sentence: 'a dog sitting in the back of a truck flat bed'. Find frequency of the letter 'h'

Output: 1


Input: Consider Input: Sentence: 'a person in yellow pants and a blue shirt carries skis up a snowy mountain'. Find frequency of the letter 'n'


Output: 7