a,b=list(map(int,input().split()));print(([a+b,'error'][(a+b)//10]))
v=sum(map(ord,eval(input())))&31;print(('error'*(9<v)or v))
a, b = list(map(int, input().split()))
print(([a + b, "error"][(a + b) // 10]))

v = sum(map(ord, eval(input()))) & 31
print(("error" * (9 < v) or v))

-a, b = list(map(int, input().split())) -print(([a + b, "error"][(a + b) // 10])) +v = sum(map(ord, eval(input()))) & 31 +print(("error" * (9 < v) or v))