#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;

void calcSum(string str1, string str2){
    int c = 0;
    string str = "";
    if (str1.size() > str2.size()){
        swap(str1, str2);
    }
    for (int i=0;i<(int)str1.size();i++){
        int sum = (str1[i] - '0') + (str2[i] - '0') + c;
        if (sum >= 10){
            str += (sum % 10) + '0';
            c = 1;
        }else{
            str += sum + '0';
            c = 0;
        }
    }
    for (int i=(int)str1.size();i<(int)str2.size();i++){
        int sum = (str2[i] - '0') + c;
        if (sum >= 10){
            str += (sum % 10) + '0';
            c = 1;
        }else{
            str += sum + '0';
            c = 0;
        }
    }
    if (c == 1)
        str += '1';
    reverse(str.begin(), str.end());
    if (str.size() > 80){
        cout << "overflow" << endl;
    }else{
        cout << str << endl;
    }
}

int main()
{
    int n;
    string str1, str2;
    
    cin >> n;
    for (int i=0; i<n; i++) {
        cin >> str1;
        cin >> str2;
        reverse(str1.begin(), str1.end());
        reverse(str2.begin(), str2.end());
        calcSum(str1, str2);
    }

    return 0;
}