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

Input: Consider Input: Sentence: 'young girl playing with refrigerator magnet while kneeling on floor'. Find frequency of the letter 'n'

Output: 6


Input: Consider Input: Sentence: 'a group of workers washing and cleaning fruits and vegetables'. Find frequency of the letter 'i'

Output: 3


Input: Consider Input: Sentence: 'a child on a small lap top sitting out in the open outdoors'. Find frequency of the letter 't'


Output: 6