Exercise: reverse a string

Write a function function reverse(s) that returns a new string made of the characters of the string s in reverse order.

• reverse("hello") → "olleh"
• reverse("привет") → "тевирп"
• reverse("ab cd") → "dc ba"

Constraints: s has 0 to 100 characters — Latin and Russian letters, digits and spaces; there are no emoji or other characters that take two places in a string. For the empty string "" the result is the empty string "".

Do not add extra imports unless the task says so explicitly.