A, B = map(int, input().split())
result = []
while(A!=0 or B!=0):
result.append(A+B)
A, B = map(int, input().split())
for i in range(len(result)):
print(result[i])
A, B = map(int, input().split())
while(A!=0 or B!=0):
print(A + B)
A, B = map(int, input().split())
while True:
try:
A, B = map(int, input().split())
print(A + B)
except EOFError:
break
https://www.geeksforgeeks.org/handling-eoferror-exception-in-python/
예외처리 : https://wikidocs.net/30
N = input()
num = int(N); sum = 0; cnt = 0
while True:
sum = (num % 10) + (num // 10) # (1)
num = (num % 10 * 10) + (sum % 10) # (2)
cnt += 1
if num == int(N): # (3)
break
print(cnt)