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

Ex Input:
Sentence: 'people plating cake in an office meeting room'. Find frequency of the letter 'g'

Ex Output:
2


Ex Input:
Sentence: 'a cat that is standing next to an open suitcase'. Find frequency of the letter 'e'

Ex Output:
3


Ex Input:
Sentence: 'a tall church tower with a clock on each of it's sides'. Find frequency of the letter 'h'

Ex Output:

4