n = int(eval(input()))



for i in range(0, n):

    a = int(eval(input()))

    b = int(eval(input()))

    if a + b >= 10 ** 80:

        print("overflow")

    elif a >= 10 ** 80:

        print("overflow")

    elif b >= 10 ** 80:

        print("overflow")

    else :

        print((a + b))
n = int(eval(input()))



for i in range(0, n):

    a = int(eval(input()))

    b = int(eval(input()))

    if len(str(a + b)) > 80:

        print("overflow")

    elif len(str(a)) > 80:

        print("overflow")

    elif len(str(b)) > 80:

        print("overflow")

    else :

        print((a + b))
n = int(eval(input()))
for i in range(0, n):
    a = int(eval(input()))
    b = int(eval(input()))
    if a + b >= 10**80:
        print("overflow")
    elif a >= 10**80:
        print("overflow")
    elif b >= 10**80:
        print("overflow")
    else:
        print((a + b))

n = int(eval(input()))
for i in range(0, n):
    a = int(eval(input()))
    b = int(eval(input()))
    if len(str(a + b)) > 80:
        print("overflow")
    elif len(str(a)) > 80:
        print("overflow")
    elif len(str(b)) > 80:
        print("overflow")
    else:
        print((a + b))

-    if a + b >= 10**80: +    if len(str(a + b)) > 80: -    elif a >= 10**80: +    elif len(str(a)) > 80: -    elif b >= 10**80: +    elif len(str(b)) > 80: