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

Sentence: 'a river with a long dragon boat in it and rowers on the boat in sets of two, along with two other people'. Find frequency of the letter 'h'
4

Sentence: 'two bears swim in a blue pool of water'. Find frequency of the letter 'o'
4

Sentence: 'a table and many different pots in a room'. Find frequency of the letter 't'

3

