TASK DEFINITION: In this task, you need to count the number of vowels (letters 'a', 'e', 'i', 'o', 'u') / consonants (all letters other than vowels) in the given sentence.
PROBLEM: Sentence: 'people stand and sit in a square in a european city'. Count the number of vowels in the given sentence.

SOLUTION: 19

PROBLEM: Sentence: 'small train pulling passengers like something you see in an amusement park'. Count the number of vowels in the given sentence.

SOLUTION: 24

PROBLEM: Sentence: 'a small boy is happy and playing outside'. Count the number of vowels in the given sentence.

SOLUTION:
12