"""
Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).

For example, the 32-bit integer ’11' has binary representation 00000000000000000000000000001011, so the function should return 3.

Credits:
Special thanks to @ts for adding this problem and creating all test cases.
"""
a = 0xf3
count = 0
while a > 0:
    print (a % 2)
    if a % 2:
        count = count + 1
    a = a // 2
print (count)
