# How does a=2 twice in this code sample? [closed]

I am just starting out learning code.

The output of the following code is OOOXOXOO, but I don't see how X can be printed twice. How does a=2 more than once?

a = 1
while a < 3:
b = 1
while b < 3:
if a == 2:
print ("X"),
print ("O"),
b = b + 1
print ("O"),
a = a + 1