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

Ex Input:
Sentence: 'the ingredients are ready on the wooden table'. Find frequency of the letter 'w'

Ex Output:
1


Ex Input:
Sentence: 'a man riding his skateboard down low as he turns'. Find frequency of the letter 'g'

Ex Output:
1


Ex Input:
Sentence: 'long hallway of a bus or train station'. Find frequency of the letter 'a'

Ex Output:

5