s="overflow"

n=eval(input())

for i in range(n):

  a=input()

  b=input()

  if len(a)>80 or len(b)>80: print(s)

  else:

    tmp=int(a)+int(b)

    if len(str(tmp))>80: print(s)

    else: print(tmp)
m=10**80

n=eval(input())

for i in range(n):

  s="overflow"

  a=eval(input())

  b=eval(input())

  if a<m and b<m:

    tmp=a+b

    if tmp<m: s=tmp

  print(s)
s = "overflow"
n = eval(input())
for i in range(n):
    a = input()
    b = input()
    if len(a) > 80 or len(b) > 80:
        print(s)
    else:
        tmp = int(a) + int(b)
        if len(str(tmp)) > 80:
            print(s)
        else:
            print(tmp)

m = 10**80
n = eval(input())
for i in range(n):
    s = "overflow"
    a = eval(input())
    b = eval(input())
    if a < m and b < m:
        tmp = a + b
        if tmp < m:
            s = tmp
    print(s)

-s = "overflow" +m = 10**80 -    a = input() -    b = input() -    if len(a) > 80 or len(b) > 80: -        print(s) -    else: -        tmp = int(a) + int(b) -        if len(str(tmp)) > 80: -            print(s) -        else: -            print(tmp) +    s = "overflow" +    a = eval(input()) +    b = eval(input()) +    if a < m and b < m: +        tmp = a + b +        if tmp < m: +            s = tmp +    print(s)