#include <cstdio>
  2 #include <iostream>
  3 #include <vector>
  4 #include <cstring>
  5 using namespace std;
  6 
  7 int main(){
  8   int n;
  9   cin >> n;
 10   while( n-- > 0 ){
 11     string num1, num2;
 12     cin >> num1 >> num2;
 13     char sum[101];
 14     int degit = 0;
 15     for( int i = 0; i < 101; i++ ) sum[i] = '0';
 16     for( int i = 0; i < num1.size(); i++ ){
 17       sum[100-i] = num1[num1.size()-i-1];
 18     }
 19     int d;
 20     for( int i = 0; i < num1.size() || i < num2.size() || degit != 0; i++ ){
 21       int now;
 22       if( i < num2.size() ){
 23         now = (int)(sum[100-i]-'0') + (int)(num2[num2.size()-i-1]-'0') + degit;
 24       }else{
 25         now = (int)(sum[100-i]-'0') + degit;
 26       }
 27       sum[100-i] = (char)(now%10)+'0';
 28       if( now >= 10 ) degit = 1;
 29       else degit = 0;
 30       d = i;
 31     }
 32     if( d < 80 ){
 33       for( int i = 100-d; i < 101; i++ ) cout << sum[i];
 34       cout << endl;
 35     }else{
 36       cout << "overflow" << endl;
 37     }
 38   }