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

Ex Input:
Sentence: 'a white and blue plate topped with meat and a salad'. Find frequency of the letter 'u'

Ex Output:
1


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 fancy vase holding onto a single flower'. Find frequency of the letter 'e'

Ex Output:

3