using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace National_Budget
{
    class Program
    {
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            List<string> ans = new List<string>();

            for (int i = 0; i < n; ++i)
            {
                string line1 = Console.ReadLine();
                string line2 = Console.ReadLine();

                if (line1.Length > 80 || line2.Length > 80)
                {
                    ans.Add("overflow");
                }
                else if (line1.Length <= 10 && line2.Length <= 10)
                {
                    ans.Add((int.Parse(line1) + int.Parse(line2)).ToString()); ;
                }
                else
                {
                    List<int> n3 = new List<int>();
                    List<int> temp1 = new List<int>();
                    List<int> temp2 = new List<int>();

                    if (line1.Length >= line2.Length)
                    {
                        foreach (char item in line1)
                        {
                            temp1.Add(int.Parse(item.ToString()));
                        }
                        foreach (char item in line2)
                        {
                            temp2.Add(int.Parse(item.ToString()));
                        }
                    }
                    else
                    {
                        foreach (char item in line2)
                        {
                            temp1.Add(int.Parse(item.ToString()));
                        }
                        foreach (char item in line1)
                        {
                            temp2.Add(int.Parse(item.ToString()));
                        }
                    }
                    temp1.Reverse();
                    temp2.Reverse();
                    int x = 0;
                    for (int j = 0; j < temp1.Count; ++j)
                    {
                        int temp;

                        if (j < temp2.Count)
                        {
                            temp = temp1[j] + temp2[j] + x;
                        }
                        else
                        {
                            temp = temp1[j] + x;
                        }

                        if (temp >= 10)
                        {
                            n3.Add(temp - 10);
                            if (j != temp1.Count - 1)
                            {
                                x = 1;
                            }
                            else
                            {
                                temp1.Add(0);
                            }
                        }
                        else
                        {
                            n3.Add(temp);
                            x = 0;
                        }
                    }

                    if (n3.Count > 80)
                    {
                        ans.Add("overflow");
                    }
                    else
                    {
                        n3.Reverse();
                        List<string> temp = new List<string>();
                        foreach (int item in n3)
                        {
                            temp.Add(item.ToString());

                        }
                        string hi = String.Join("", temp);
                        ans.Add(hi);
                    }

                }

            }

            foreach (string item in ans)
            {
                Console.WriteLine(item);
            }
        }
    }
}



Measured memory_bytes: 20052