How print(n) answer is 5?

Question

n = 0
a = 5
b = 3
while a> 0:
b +=1
a -= 1
n += 1
print(n)

Answer 1

b=4
a=4
n=1

b=5
a=3
n=2

b=6
a=2
n=3

b=7
a=1
n=4

b=8
a=0
n=5