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

Ex Input:
Sentence: 'a close up of a plate with a whole carrot'. Find frequency of the letter 'w'

Ex Output:
2


Ex Input:
Sentence: 'a train station with a train pulling into the platform'. Find frequency of the letter 'i'

Ex Output:
6


Ex Input:
Sentence: 'a kitchen being remodeled covered in lots of clutter'. Find frequency of the letter 'k'

Ex Output:

1