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

Sentence: 'some people sitting on surfboards in the water'. Find frequency of the letter 't'
4

Sentence: 'a row of vintage cars in a grassy field'. Find frequency of the letter 'v'
1

Sentence: 'an old timey image of a clock attached to the outside of a building wall,'. Find frequency of the letter 'l'

5