#include <iostream>
#include <cstdio>
using namespace std;
int main(){
  int n;
  cin >> n;
  while(n--){

  string num1,num2;
  cin >> num1 >> num2;

  if(num1.size() < num2.size())swap(num1,num2);
  if(num1.size() > 80){
    cout << "overflow" << endl;
    continue;
  }
  int m = num1.size()-num2.size();
  int M = num1.size();
  string n1="",n2="";
  for(int i = 0 ; i < m ; i++ )n2+='0';
  n2 = n2 + num2;
  string nn1="",nn2="";
  for(int i = M-1 ; i >= 0 ; i-- ){
    nn1+=num1[i];
    nn2+=n2[i];
  }
  string ans="",ansi="";
  int t = 0;

  for(int i = 0 ; i < num1.size() ; i++ ){
    if(t + (nn1[i] - '0') + (nn2[i] - '0') >= 10){
      ans += (t + (nn1[i] - '0') + (nn2[i] - '0') - 10) + '0' ;
      t = 1;
    } else {
      ans += (char)(t + (nn1[i]-'0') + (nn2[i]-'0') + '0');
      t = 0;
    }
  }

    if(t==1)ans+='1';
    for(int i = ans.size()-1 ; i >= 0 ; i--){
      ansi += ans[i];
    }
    if(ansi.size() > 80){
      cout << "overflow" << endl;
    }else cout << ansi << endl;
    }
  return 0;
}