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

Ex Input:
Sentence: 'a woman holds the reins of a saddled horse'. Find frequency of the letter 'm'

Ex Output:
1


Ex Input:
Sentence: 'different sets of luggage in a baggage claim area'. Find frequency of the letter 'r'

Ex Output:
2


Ex Input:
Sentence: 'a man eating a pastry with a woman leaning on him'. Find frequency of the letter 'a'

Ex Output:

8