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

Ex Input:
Sentence: 'a tower with some bright lights and clocks on it'. Find frequency of the letter 'h'

Ex Output:
3


Ex Input:
Sentence: 'a very big nice looking living room with nice furnishings'. Find frequency of the letter 'e'

Ex Output:
3


Ex Input:
Sentence: 'a passenger jet that is flying in the air'. Find frequency of the letter 'p'

Ex Output:

1