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

Sentence: 'a half eaten doughnut in a persons hand'. Find frequency of the letter 'h'
3

Sentence: 'an image of a street sign with a corner restaurant'. Find frequency of the letter 'u'
1

Sentence: 'a person's hand on a suitcase that is open'. Find frequency of the letter 'h'

2

