"""
输入两个数A和B
A:111111001010101001
B:1001010101011010010100
"""
def bignummul(num_a, num_b):
a = min(num_a, num_b)
b = max(num_a, num_b)
res = 0
str_a = str(a)
alen = len(str_a)
for i in range(alen - 1, -1, -1):
if str_a[i] == '0':
continue
else:
res += b * 10**(alen - 1 - i)
return res
a = 111111001010101001
b = 1001010101011010010100
print(bignummul(a, b))