#include<iostream>
#include<string>
#include<algorithm>
#define N 1000
using namespace std;
int main(){
  
  int n,anum,bnum;
  cin >> n;
  for(int i = 0;i < n;i++){
    string a,b,c,tmp;
    cin >> a >> b;
      if(a.size() < b.size()){swap(a,b);}
      for(int k = 0;k< a.size();k++)
	c[k] = '0';
      for(int k = 0;k < b.size();k++){
	c[k] = b[b.size()-1-k];
      }
      for(int k = 0;k < a.size();k++)
	   {b[k] = c[k]; c[k] = a[k];}
      for(int k = 0;k < a.size();k++){
      	a[a.size()-k-1] = c[k];
	  tmp[k] = '0';}

      //for(int k = 0;k <= a.size();k++)
      //	cout << a[k] ;
      //cout << endl;
      //for(int k = 0;k <= a.size();k++)
      //	cout << b[k] ;
      //cout << endl;
      
        for(int k = 0;k < a.size();k++){
	  //  cout << a[k] << b[k] << " " <<tmp[k] << endl;
	c[k] = a[k] + b[k] + tmp[k] -'0' -'0';
	
	if(c[k] > '9'){ tmp[k+1] = '1'; c[k] = c[k] - ':' + '0'; }
	}

	if(a.size() < 80 && tmp[a.size()] == '1'){ cout << tmp[a.size()];
      for(int k = a.size()-1;k >=0;k--){
	cout << c[k];  //cout << tmp[0];
	}

      cout << endl;
	} else {cout <<"overflow"<<endl; }
  }
}