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

Ex Input:
Sentence: 'a woman holds the reins of a saddled horse'. Find frequency of the letter 'm'

Ex Output:
1


Ex Input:
Sentence: 'a white bowl filled with peeled orange slices'. Find frequency of the letter 's'

Ex Output:
2


Ex Input:
Sentence: 'a large group of people skateboarding down a city street together with no cars on the street'. Find frequency of the letter 'e'

Ex Output:

11