"""
In this simple assignment you are given a number and have to
make it negative. But maybe the number is already negative?

Example:
make_negative(1);  # return -1
make_negative(-5); # return -5
make_negative(0);  # return 0
Notes:

The number can be negative already, in which case no change
is required.
Zero (0) is not checked for any specific sign. Negative
zeros make no mathematical sense.
"""

def make_negative(number):
    return abs(number)*(-1) if number != 0 else 0

print("Tests:")
print(make_negative(42))
print(make_negative(-9))
print(make_negative(0))