ModAdd

import fileinput
import time

#t1 = time.time()

with fileinput.input(['z']) as input:
    a = input.readline().rstrip()
    b = input.readline().rstrip()
    len_a = len(a)
    len_b = len(b)
    res = []
    d = {}
    for i in range(19):
        d[i] = str(i % 10)
    z = min(len_a, len_b)
    for i in range(-z, 0):
        a_i = int(a[i])
        b_i = int(b[i])
        #if (a_i, b_i) not in d:
        #    d[(a_i, b_i)] = str((a_i + b_i) % 10)
        res.append(d[a_i + b_i])
        #try:
        #res.append(d[(a_i, b_i)])
        #except KeyError:
         #   res.append(d[(b_i, a_i)])
    if len_a > len_b:
        res = list(a[0:len_a - z]) + res
    elif len_a < len_b:
        res = list(b[0:len_b - z]) + res
    print(''.join(res).lstrip('0'))

#t2 = time.time()

#print(t2-t1)

Test 1

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 2

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 3

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 4

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 5

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 6

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 7

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 8

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 9

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...

Test 10

Verdict: RUNTIME ERROR

Traceback (most recent call last):
  File "input/code.py", line 7, in <module>
    a = inp...