Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func main() {
	scanner.Split(bufio.ScanWords)

	const maxCapacity = 512 * 1024
	buf := make([]byte, maxCapacity)
	scanner.Buffer(buf, maxCapacity)

	n := nextInt()
	maxint, _ := new(big.Int).SetString("100000000000000000000000000000000000000000000000000000000000000000000000000000000", 10)

	for i := 0; i < n; i++ {
		aStr := nextString()
		bStr := nextString()

		a, _ := new(big.Int).SetString(aStr, 10)
		b, _ := new(big.Int).SetString(bStr, 10)
		c := big.NewInt(0).Add(a, b)

		if c.Cmp(maxint) < 0 {
			fmt.Println(c)
		} else {
			fmt.Println("overflow")
		}
	}
}

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

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

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

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

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

if __name__ == '__main__':
    main()

Python: 
if __name__ == '__main__':
    n = (int)(input())
    for _ in range(n):
        sNumber = (int)(input())
        tNumber = (int)(input())
        uNumber = sNumber+tNumber
        print("overflow" if uNumber >= 10**80 else uNumber)

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

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

Python: from math import log10
n = int(input())
for i in range(n):
    a = int(input())
    b = int(input())
    c = a+b
    if (log10(c) > 80):
        print("overflow")
    else:
        print(c)

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

Python: n=int(input())
for n in range(n):
	a=int(input())
	b=int(input())
	c=a+b
	if a>=int(1e80) or b>=int(1e80) or c>=int(1e80):
		print("overflow")
	else:
		print(c)

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

Python: import sys
import itertools

dataset_num = int(input())

class Overflow(Exception):
    pass

for _ in range(dataset_num):
    try:
        k1 = input()
        k2 = input()
        k1_val = [0] * 80
        k2_val = [0] * 80

        if len(k1) > 80 or len(k2) > 80:
            raise Overflow()
        
        for i, x in enumerate(reversed(k1)):
            k1_val[i] = int(x)

        for i, x in enumerate(reversed(k2)):
            k2_val[i] = int(x)
        
        res = [0] * 80
        for i in range(0, 80):
            res[i] += k1_val[i] + k2_val[i]
            if res[i] >= 10:
                res[i+1] += 1
                res[i] -= 10
        sumstr = "".join([str(x) for x in itertools.dropwhile(lambda x: x == 0, reversed(res))])
        if len(sumstr) > 80:
            raise Overflow()

        print(sumstr)
    except Overflow:
        print("overflow")

Python: N = 10 ** 80
for i in range(int(input())):
    n = int(input()) + int(input())
    print(n if n < N else 'overflow')

Python: n=int(input())
for _ in range(n):
    a=int(input())
    b=int(input())
    ab=a+b
    print(ab if ab<=10**80 else "overflow")

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)