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

Sentence: 'the little girl is flying her kite in the field'. Find frequency of the letter 'i'
7

Sentence: 'a group of people seated in chairs together and facing the same direction, with one man holding a soccer ball in his hands'. Find frequency of the letter 'm'
2

Sentence: 'a tugboat in the water has two occupants'. Find frequency of the letter 'a'
5