__author__ = 'zhanghe'

def add(x, y):

"""

result = [int(p)+int(q) for i_p, p in enumerate(('0'*(max(len(x), len(y))-len(x))+str(x))[::-1]) for i_q, q in enumerate(('0'*(max(len(x), len(y))-len(y))+str(y))[::-1]) if i_p == i_q]

for index, v in enumerate(result):

if v >= 10:

result[index], k = v % 10, v / 10

if index+1 < max(len(str(x)), len(str(y))):

result[index+1] += k

else:

result.append(k)

return ''.join([str(i) for i in result][::-1])

def multiply(x, y):

"""

i, result = 0, '0'

for m in [int(m) for m in x][::-1]:

k, t = 0, []

t.extend([0]*i)

for n in [int(n) for n in y][::-1]:

t.append((int(m)*int(n)+k) % 10)

k = (int(m)*int(n)+k) / 10

i += 1

if k > 0:

t.append(k)

result = add(result, ''.join([str(item) for item in t[::-1]]))

return result

def test_add():

"""

# 连续进位

a = '8838'

b = '3968'

print add(a, b)

print int(a)+int(b)

a_1 = '821111111111111181'

b_1 = '94222222222222226200'

print add(a_1, b_1)

print int(a_1)+int(b_1)

a_2 = '8211111111111333311181'

b_2 = '94222222222222226200'

print add(a_2, b_2)

print int(a_2)+int(b_2)

# 和的长度超过原始数值

a_3 = '82111111111116611181'

b_3 = '94222222222222226200'

print add(a_3, b_3)

print int(a_3)+int(b_3)

def test_multiply():

"""

a_1 = '821111111111111181'

b_1 = '94222222222222226200'

print multiply(a_1, b_1)

print int(a_1)*int(b_1)

a_2 = '8211111111111333311181'

b_2 = '94222222222222226200'

print multiply(a_2, b_2)

print int(a_2)*int(b_2)

a_3 = '82111111111116611181'

b_3 = '94222222222222226200'

print multiply(a_3, b_3)

print int(a_3)*int(b_3)

if __name__ == '__main__':

test_add()

test_multiply()