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

Input: Consider Input: Sentence: 'a person is water skiing and there are birds flying around above them'. Find frequency of the letter 'n'

Output: 5


Input: Consider Input: Sentence: 'a snowboarder making a jump of a snowy ledge'. Find frequency of the letter 'o'

Output: 4


Input: Consider Input: Sentence: 'the catcher poised ready to return the base ball'. Find frequency of the letter 'p'


Output: 1