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

using namespace std;

void Swap(string&, string&);
vector<int> Atoi(string);

int main(){
  int i, j, n, a, b;
  vector<int> x, y, z;
  string s, t;

  cin >> n;

  for(i=0; i<n; ++i){
    cin >> s >> t;
    if(s.size() < t.size()) Swap(s, t);

    if(s.size() < 80){
      x = Atoi(s);
      y = Atoi(t);

      b = 0;
      for(j=0; j<y.size(); ++j){
	a = x[j] + y[j] + b;
	if(a >= 10){
	  a -= 10;
	  b = 1;
	}else{
	  b = 0;
	}
	z.push_back(a);
      }

      for(j=y.size(); j<x.size(); ++j){
	a = x[j] + b;
	if(a >= 10){
	  a -= 10;
	  b = 1;
	}else{
	  b = 0;
	}
	z.push_back(a);
      }
      if(b == 1) z.push_back(1);

      if(z.size() < 80){
	for(j=z.size()-1; j>=0; --j)
	  cout << z[j];
	cout << endl;
      }else{
	cout << "overflow" << endl;
      }

      x.clear();
      y.clear();
      z.clear();

    }else{
      cout << "overflow" << endl;
    }
  }
  return 0;
}

void Swap(string& s, string& t){
  string u;
  u = s;
  s = t;
  t = u;
}

vector<int> Atoi(string s){
  int i, n;
  vector<int> x;

  for(i=s.size()-1; i>=0; --i){
    n = s[i]-48;
    x.push_back(n);
  }

  return x;
}