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

Input: Consider Input: Sentence: 'a young elephant is touching a bigger elephant with its trunk'. Find frequency of the letter 'i'

Output: 5


Input: Consider Input: Sentence: 'two giraffes standing next to some trees'. Find frequency of the letter 'f'

Output: 2


Input: Consider Input: Sentence: 'woman standing in bedroom with unmade bed in residential home'. Find frequency of the letter 'b'


Output: 2