Why are all the values being appended to the list winning_numbers?

I am working in Jupyter Notebook with Python 3.6. I do not understand why all the values are being appended to winning_numbers instead of losing_numbers where they should.

My code:

import numpy as np

winning_numbers = []
losing_numbers = []

limit = 11

for x in range(1, limit):

    if x%2 == 0:

        if x-1 or x/2 in losing_numbers:
            winning_numbers.append(x)

        elif x-1 and x/2 in winning_numbers:
            losing_numbers.append(x)

    if x%2 == 1:

        if x-1 == 0:
            winning_numbers.append(x)

        elif x-1 or (x-1)/2 in losing_numbers:
            winning_numbers.append(x)

        elif x-1 and (x-1)/2 in winning_numbers:
            losing_numbers.append(x)

print("Winning Numbers: ", winning_numbers)
print("Losing Numbers: ", losing_numbers)

My output is:

Winning Numbers:  [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
Losing Numbers:  []

The output should be:

Winning Numbers: [1, 3, 4, 5, 7, 9]
Losing Numbers: [2, 6, 8, 10]