def func(numbers = [1, 1]):
for a in range(10**len(numbers)):
print(numbers)
for a in range(a_start, a_end + 1):
for b in range(b_start, b_end + 1):
print(a, b)
from itertools import product
for a,b in product(range(a_start, a_end + 1), range(b_start, b_end + 1)):
print(a,b)