A, B = [int(x) for x in input().split(" ")]



ans = A + B



print(("error" if ans >= 10 else ans))
l = list(map(int, input().split()))



ans = l[0] + l[1]



if ans >= 10:

    print("error")

else:

    print(ans)

    

    
A, B = [int(x) for x in input().split(" ")]
ans = A + B
print(("error" if ans >= 10 else ans))

l = list(map(int, input().split()))
ans = l[0] + l[1]
if ans >= 10:
    print("error")
else:
    print(ans)

-A, B = [int(x) for x in input().split(" ")] -ans = A + B -print(("error" if ans >= 10 else ans)) +l = list(map(int, input().split())) +ans = l[0] + l[1] +if ans >= 10: +    print("error") +else: +    print(ans)