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: if __name__ == '__main__':
    # ??????????????\???
    loop = int(input())
    for i in range(loop):
        num1 = int(input())
        num2 = int(input())

        # ???????????????
        result = num1 + num2

        # ???????????????
        if len(str(result)) > 80:
            print('overflow')
        else:
            print(result)

Python: n=int(input())
for _ in range(n):
    a=int(input())
    b=int(input())
    ab=a+b
    print(ab if ab<10**79 else "overflow")

Python: n = int(input())

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

Python: import math
n = input();
for var in range(0, int(n)) :
	c1 = input();
	c2 = input();
	sum = int(c1) + int(c2);
	if(math.log10(sum) + 1 > 80) :
		print("overflow");
	else :
		print(sum);

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

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

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

import sys
import os
import math

def is_overflow(v):
    s = str(v)
    if len(s) > 80:
        return True
    else:
        return False

N = int(input())
for i in range(N):
    v0 = int(input())
    v1 = int(input())
    if is_overflow(v0) or is_overflow(v1):
        print('overflow')
    elif is_overflow(v0 + v1):
        print('overflow')
    else:
        print(v0 + v1)

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

lim = 1000000000000000000000000000000000000000000000000000000000000000000000000000000 

def largeBudget(a, b):
  if a >= lim or b >= lim: print("overflow")
  elif a+b >= lim: print("overflow")
  else: print("%d"%(a+b))

N = int(input())
for i in range(N):
  a = int(input())
  b = int(input())
  largeBudget(a, b)

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: 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] * 100
        k2_val = [0] * 100

        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] * 100 
        for i in range(0, 100):
            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()
        if len(sumstr) == 0:
            sumstr = "0"

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

Python: import math

n = int(input());

for i in range(0,n):
    
    num1 = int(input());
    num2 = int(input());
    total = num1 + num2;

    if len(str(total)) > 80:
        print("overflow");
    else:
        print(total);

Python: n = int(input())
for i in range(n):
    a = int(input())
    b = int(input())
    s = a + b
    if s >= 10**80:
        print('overflow')
    else:
        print(s)

Python: for i in range(int(input())):
    try:
        a = sum([int(j) for j in input().split()])
    except:
        print("overflow")
    else:
        print(a)

Python: import math
a=int(input())
b=int(input())
c=a+b
for x in range(80):
	c=math.floor(c/10)
if(c>=1):
	print("overflow")
else:
	print(a+b)

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

Python: import sys
import math

n = int(sys.stdin.readline())

for i in range(n):
    n1 = int(sys.stdin.readline())
    n2 = int(sys.stdin.readline())
    if n1+n2<100000000000000000000000000000000000000000000000000000000000000000000000000000000 :
        print(n1+n2)
    else:
        print("overflow")

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

Python: import math

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

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

def largeBudget(a, b):
  if a >= 1e+80 or b >= 1e+80: print("overflow")
  elif a+b >= 1e+80: print("overflow")
  else: print("%d"%(a+b))

N = int(input())
for i in range(N):
  a = int(input())
  b = int(input())
  largeBudget(a, b)

Python: n = int(input())
for i in range(n):
    a = int(input())
    b = int(input())
    c = a+b
    if c >= (10**80):
        print("overflow")
    else:
        print(c)

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

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

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: # 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**79:
        ans.append("overflow")
    else:
        ans.append(str(s))
print("\n".join(ans))

Python: import math

n = int(input());

for i in range(n):
    
    num1 = int(input());
    num2 = int(input());
    total = num1 + num2;

    if len(str(total)) > 80:
        print("overflow");
    else:
        print(total);

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

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