Go: package main

import (
	"bufio"
	"fmt"
	"math/big"
	"os"
	"strconv"
)

var sc = bufio.NewScanner(os.Stdin)

func main() {
	sc.Scan()
	dataset, _ := strconv.Atoi(sc.Text())
	var firstdata *big.Int

	for i := 0; i < dataset*2; i++ {
		n := new(big.Int)
		sc.Scan()
		data, _ := n.SetString(sc.Text(), 10)

		if i%2 == 0 {
			firstdata = data
			continue
		}

		result := new(big.Int)
		if result := result.Add(data, firstdata); len(result.String()) > 80 {
			fmt.Println("overflow")
			continue
		} else {
			fmt.Println(result)
		}
	}
}

Python: for _ in range(int(input())):
    a=int(input())
    b=int(input())
    print([a+b,'overflow'][len(str(a+b))>80])

Python: if __name__ == '__main__':

	n = int(input())

	for i in range(n):
		a = int(input())
		b = int(input())

		if len(str(a+b)) > 80:
			print("overflow")
		else:
			print(a+b)

Python: # ?????¶??????????±???????????????°??????
import sys

def main():
    n = int(sys.stdin.readline().strip())

    for _ in range(n):
        x = sys.stdin.readline().strip()
        y = sys.stdin.readline().strip()

        if len(x) > 80 or len(y) > 80:
            print('overflow')
        else:
            ans = int(x) + int(y)
            if len(str(ans)) > 80:
                print('overflow')
            else:
                print(x + y)

if __name__ == '__main__':
    main()

Python: for _ in[0]*int(input()):
 s=int(input())+int(input())
 print([s,'overflow'][s>=10**80])

Python: p = int(input())
for j in range(p):
    a, b = int(input()), int(input())
    x = str(a+b)
    print("overflow" if len(x)>80 else a+b)

Python: t=int(input())
for num in range(t):
	a=int(input())
	b=int(input())
	if len(str(a))<=80 and len(str(b))<=80 and len(str(a+b))<=80:
		print(a+b)
	else:
		print("overflow")

Python: n = int(input())

for i in range(n):
    x = input()
    y = input()
    ans = int(x) + int(y)
    if len(x) > 80 or len(y) > 80 or len(str(ans)) > 80:
        print("overflow")
    else:
        print(ans)

Python: import math

n1 = input();
n2 = input();
sum = int(n1) + int(n2);

if int(math.log10(sum)) + 1 > 80 :
	print("overflow");
else :
	print(sum);

Python: # -*- coding: utf-8 -*-
N = int(input())

for _ in range(N):
    a = int(input())
    b = int(input())
    s = str(a + b)
    limit = '1' + '0'*79
    if len(s) <= limit:
        print(s)
    else:
        print('overflow')

Python: n = int(input())
for _ in range(n):
    a = input()
    if len(str(a)) > 80:
        print("overflow")
        continue
    b = input()
    if len(str(b)) > 80:
        print("overflow")
        continue
    c = int(a) + int(b)
    if len(str(c)) > 80:
        print("overflow")
    else:
        print(c)

Python: n = int(input())

for i in range(n):
    a = int(input())
    b = int(input())

    if (a + b) < (10 ** 80):
        print(a + b)
    else:
        print("overflow")

Python: # python template for atcoder1
import sys
sys.setrecursionlimit(10**9)
input = sys.stdin.readline

n = int(input())
ans = []
for _ in range(n):
    a = int(input())
    b = int(input())
    s = a+b
    if s > 10**80-1:
        ans.append("overflow")
    else:
        ans.append(str(s))
print("\n".join(ans))

Python: import math

n = int(input())
for i in range(n):
    for i in range(2):
        x = int(input())
        y = int(input())
        result = x * y
        print(result) if math.log10(result) + 1 < 10 ** 80 else print("overflow")

Python: # -*- coding:utf-8 -*-

def main():
    for i in range(int(input())):
        a=int(input())+int(input())
        if la>=10**80:
            print("overflow")
        print(a)
            
    
if __name__ == '__main__':
    main()

Python: n = int(input())
for _ in range(n):
    s = int(input()) + int(input())
    print('overflow' if len(str(s)) > 80 else s)

Python: import sys
import math as mas

n=int(input())
for t in range(n):
	i=int(t)
	a=int(input())
	b=int(input())
	a+=b
	if a<10**80:print(a)
	else:print("overflow")
	
#for i in sys.stdin:
#	a,b=map(int,i.split())
#	print(gcd(a,b),lcm(a,b))

Python: for i in range(int(input())):
    a = int(input()) + int(input())
    if a > 2147483647:
        print("overflow")
    else:
        print(a)

Python: a=int(input())
b=int(input())
c=a+b
c=str(c)
if len(c)>80:
	print("overflow")
else:
	print(c)

Python: n =int(input())
for i in range(n):
  a =int(input())
  b=int(input())

  if (a+b)<(10 **80):
    print(a+b)
  else:
    print("overflow")

Python: if __name__ == "__main__":
    nset = int(input())

    for i in range(0,nset):
        a = int(input())
        b = int(input())
        print(a+b)

Python: n = int(input())
for i in range(n):
    x = int(input())
    y = int(input())
    if len(str(x + y)) > 80:
        print("overflow")
    else:
        print(x + y)

Python: upper = 10**81
n = int(input())
for i in range(n):
    n1 = int(input())
    if n1 >= upper:
        print("overflow")
        continue
    n2 = int(input())
    if n2 >= upper:
        print("overflow")
        continue
    print( n1 + n2 if n1+n2 < upper else "overflow")

Python: #!/usr/bin/env python
#-*- coding:utf-8 -*-

import sys
import math

n = int(input())
anss = []

for _ in range(n):
    x = int(input())
    y = int(input())
    anss.append(x+y)

for data in anss:
    print(data)

Python: print("In preparation.")

Python: n = int(input())
for i in range(n):
    num1 = int(input())
    num2 = int(input())
    num3 = num1 + num2
    k = len(str(num3))
    if k > 80:
        print("overflow")
    else:
        print(num3)

Python: upper = 10**80
n = int(input())
for i in range(n):
    n1 = int(input())
    if n1 >= upper:
        print("overflow")
        continue
    n2 = int(input())
    if n2 >= upper:
        print("overflow")
        continue
    print( n1 + n2 if n1+n2 < upper else "overflow")

Python: #!/usr/bin/env python
#-*- coding:utf-8 -*-

import sys
import math

n = int(input())
anss = []

for _ in range(n):
    x = int(input())
    y = int(input())
    if int(math.log10(x)+1) > 80:
        print("overflow")
    elif int(math.log10(y)+1) > 80:
        print("overflow")
    elif int(math.log10(x+y)+1) > 80:
        print("overflow")
    else:
        anss.append(x+y)

for data in anss:
    print(data)

Python: n=int(input())
A=[]
while True:
	try:
		x=int(input())
		A.append(x)
	except EOFError:
		break
start=0
end=start+n
for i in range(len(A)//n):
	s=sum(A[start:end])
	if s/1e80>1:
		print("overflow")
	else:
		print(s)
	start+=n
	end+=n

Python: n = int(input())
for _ in range(n):
    a, b = input(), input()
    m = abs(len(a) - len(b))
    if len(a) > len(b):
        a = '0' + a
        b = '0' * (m+1) + b
    else:
        a = '0' * m + a
        b = '0' + b
    a, b = a[::-1], b[::-1]
    
    budget = []
    flag = False
    for i in range(0, len(a), 10):
        t = int(a[i:i+10][::-1]) + int(b[i:i+10][::-1]) 
        if flag: t += 1
        t = str(t)

        if len(t) > 10:
            t = t[1:]
            flag = True
        elif i + 10 <= len(a):
            t = '0' * abs(len(t) - 10) + t
            flag = False
        else:
            flag = False
        budget.append(t)
    
    budget = ''.join(budget[::-1])
    if len(budget) < 80:
        print(budget)
    else:
        print('overflow')

Python: for _ in range(int(input())):
    a = int(input())
    b = int(input())
    s = a + b
    if s >= 1e79:
        print('overflow')
    else:
        print(s)

Python: i = int(input())
for n in range(i):
    j = int(input())
    k = int(input())
    if len(str(j + k)) >= 80:
        print("overflow")
    else:
        print(j + k)

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