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

Ex Input:
Sentence: 'a bunch of fruit sitting in a bowl, its overflowing'. Find frequency of the letter 't'

Ex Output:
4


Ex Input:
Sentence: 'many different species of sheep in display at a museum'. Find frequency of the letter 'h'

Ex Output:
1


Ex Input:
Sentence: 'a brown black and white cat  is playing with a toy banana'. Find frequency of the letter 'o'

Ex Output:

2