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

Ex Input:
Sentence: 'cooked fish and green broccoli share a single white plate'. Find frequency of the letter 'c'

Ex Output:
3


Ex Input:
Sentence: 'two indian women in colorful garb standing barefoot with two indian men'. Find frequency of the letter 'd'

Ex Output:
3


Ex Input:
Sentence: 'a blue and grey train speeding along the railway'. Find frequency of the letter 'e'

Ex Output:

5