```
class Solution(object):
def multiply(self, num1, num2):
"""
:type num1: str
:type num2: str
:rtype: str
"""
num1 = reduce(lambda x, y: x * 10 + y, [ord(i) - 48 for i in num1]) # '0' is 48 in ascii
num2 = reduce(lambda x, y: x * 10 + y, [ord(i) - 48 for i in num2])
return str(num1 * num2)
```