#include <iostream>
#include <string>
#include <vector>
#include <algorithm>

std::string add(std::string,std::string);

int main(){
  std::string n,m;
  int size;
  std::cin>>size;
  std::vector<std::string> sums;
  for(int i=0;i<size;++i){
    std::cin>>n>>m;
    std::string sum = add(n,m);
    if(sum.length()<=80)
      sums.push_back(sum); 
    else
      sums.push_back("overflow"); 
  }

  for(auto s:sums)
    std::cout<<s<<std::endl;

  return 0;
}

std::string add(std::string n,std::string m){
  if(n.length()>m.length()) std::swap(n,m);
  std::reverse(n.begin(),n.end());
  std::reverse(m.begin(),m.end());
  std::string sum;
  char c=0,s,t;
  for(int i=0;i<m.length()||c==1;++i){
    t = (i<n.length()?n[i]-'0':0)+(i<m.length()?m[i]-'0':0)+c;
    s = t%10;
    c = t/10;
    sum.push_back(s+'0');
  }
  
  std::reverse(sum.begin(),sum.end());
  sum.push_back('\0');
  return sum;
}