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

Ex Input:
Sentence: 'the child is waving a small flag as she stands near two women'. Find frequency of the letter 'g'

Ex Output:
2


Ex Input:
Sentence: 'city two way street with cars lined up on both sides'. Find frequency of the letter 'h'

Ex Output:
2


Ex Input:
Sentence: 'a woman talks on a cell phone while setting on a bench at a bus stop on a sidewalk'. Find frequency of the letter 'e'

Ex Output:

6