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

Input: Consider Input: Sentence: 'two people and two children walking in a building'. Find frequency of the letter 'd'

Output: 3


Input: Consider Input: Sentence: 'a large group of motorcycles parked along a street'. Find frequency of the letter 'a'

Output: 5


Input: Consider Input: Sentence: 'people are standing in the sand on the beach flying a kite'. Find frequency of the letter 'n'


Output: 6