How 6 is the output?

Question

def f(a):
x=a**2
y=0

while x>1:
x-=1
y+=2
return y

print (f(1)+f(2))

Answer 1

Copy that prog and add lots of print

Answer 2

If a=1 in f function while loop will executed 0 time ( because 1**2 =1 and 1 = 1). In case a = 2, 2**2 = 4, so loop executes 3 times and y will be 6.