#include <iostream>
#include <algorithm>
#include <string>
 
using namespace std;
 
char calc(char x,char y,char z,bool &C){
  int a = x - '0',b = y - '0',c = z - '0';
  int d = a + b + c;
 
  if(d >= 10){
    C = true;
    d -= 10;
  }
 
  return d + '0';
}
 
string sum(string a,string b){
  string res = "";
 
  reverse(a.begin(),a.end());
  reverse(b.begin(),b.end());
 
  int length;
  if((int)a.size() > (int)b.size()){
    length = (int)a.size();
     
    for(int i = (int)b.size() ; i < length ; i++){
      b += '0';
    }
 
  }
  else{
    length = (int)b.size();
 
    for(int i = (int)a.size() ; i < length ; i++){
      a += '0';
    }
 
  }
 
  for(int i = 0 ; i <= length ; i++)
    res += '0';
 
  for(int i = 0 ; i < length ; i++){
    bool C = false;
    res[i] = calc(a[i],b[i],res[i],C);
    if(C) res[i+1] = ((res[i+1]-'0') + 1) + '0';
  }
 
  for(int i = length ;; i--){
     
    if(res[i] == '0'){
      res.erase(res.begin()+i);
    }
    else{
      break;
    }
     
  }
 
  reverse(res.begin(),res.end()); 
 
  return res;
}

int main(){
  int n;

  cin >> n;
  while(n--){
    string a,b;

    cin >> a >> b;
    string c = sum(a,b);
    
    if((int)c.size() >= 80) cout << "overflow" << endl;
    else cout << c << endl;
  }

  return 0;
}