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

Ex Input:
Sentence: 'young boy flying kite in large field at outdoor event'. Find frequency of the letter 'y'

Ex Output:
3


Ex Input:
Sentence: 'a group of people are playing soccer on a beach'. Find frequency of the letter 'l'

Ex Output:
2


Ex Input:
Sentence: 'man sitting on the edge of a couch with a bat'. Find frequency of the letter 'h'

Ex Output:

3