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

Ex Input:
Sentence: 'a man in a suit makes the first slice into a cake'. Find frequency of the letter 't'

Ex Output:
4


Ex Input:
Sentence: 'tow birds flying by a long necked crane'. Find frequency of the letter 'f'

Ex Output:
1


Ex Input:
Sentence: 'a woman walks down a rainy street holding an umbrella'. Find frequency of the letter 'w'

Ex Output:

3