# AOJ 0015 National Budget

# Python3 2018.6.9 bal4u



n = int(eval(input()))

for i in range(n):

    a = str(eval(input()))

    b = str(eval(input()))

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

        print('overflow')

    else:

        s = str(int(a)+int(b))

        if len(s) <= 80:

            print(s)

        else:

            print('overflow')

# AOJ 0015 National Budget

# Python3 2018.6.9 bal4u



n = int(eval(input()))

for i in range(n):

    s = int(eval(input())) + int(eval(input()))

    if len(str(s)) <= 80:

        print(s)

    else:

        print('overflow')

# AOJ 0015 National Budget
# Python3 2018.6.9 bal4u
n = int(eval(input()))
for i in range(n):
    a = str(eval(input()))
    b = str(eval(input()))
    if len(a) > 80 or len(b) > 80:
        print("overflow")
    else:
        s = str(int(a) + int(b))
        if len(s) <= 80:
            print(s)
        else:
            print("overflow")

# AOJ 0015 National Budget
# Python3 2018.6.9 bal4u
n = int(eval(input()))
for i in range(n):
    s = int(eval(input())) + int(eval(input()))
    if len(str(s)) <= 80:
        print(s)
    else:
        print("overflow")

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