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

Ex Input:
Sentence: 'a glass vase sits between two statues'. Find frequency of the letter 'o'

Ex Output:
1


Ex Input:
Sentence: 'a group of people having dinner and drinking wine'. Find frequency of the letter 'r'

Ex Output:
3


Ex Input:
Sentence: 'two vases are shown with flowers in them'. Find frequency of the letter 'h'

Ex Output:

3