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

Sentence: 'two people holding their skies in a snowy resort'. Find frequency of the letter 'n'
3

Sentence: 'a man pushing a cart full of bananas'. Find frequency of the letter 'u'
2

Sentence: 'a multi-colored parrot holding its foot up to its beak'. Find frequency of the letter 'r'

3