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 train going over a bridge with some buildings in the background'. Find frequency of the letter 'd'

Ex Output:
3


Ex Input:
Sentence: 'a teal colored clock with little men on top'. Find frequency of the letter 'l'

Ex Output:

5