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

Sentence: 'a glass a rope and a pair of scissors'. Find frequency of the letter 's'
6

Sentence: 'some giraffes moving across a big grass field'. Find frequency of the letter 'e'
3

Sentence: 'giraffes are standing in the distance on a grassy land'. Find frequency of the letter 'a'

7