Stein's GCD according to given pseudo code

[wanttolearn]

Hi,
I have an assignment where I was given a pseudo code based off of Stein's algorithm to get GCD. The pseudo code provided was:
k := 0
while x and y are both even
x := x / 2
y := y / 2
k := k + 1
while x ≠ y
if x is even then x := x/2
else if y is even then y := y/2
else if x > y then x := (x – y)/2
else y := (y – x)/2
return x × 2k

I tried coding a function based off the pseudo code I was given but when I run the function, it does not solve at all. No answer is given and the code just keeps running. Can I have some help with this?

Code I wrote:

def gcd(x, y):
  k=0
  while x%2==0 and y%2==0:
    x=x/2
    y=y/2
    k=k+1
  while x%2!=0 or y%2!=0:
    while x%2==0:
      x=x/2
    while y%2==0:
      y=y/2
    while x>y:
      x=(x-y)/2
    while y>x:
      y=(y-x)/2
  return x*(2**k)

Thanks for any help!