#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <map>
#include <utility>
#include <set>
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <sstream>
#include <queue>
#include <cstring>
#include <functional>

using namespace std;

#define REP(i,a,b) for((i)=(a);(i)<(int)(b);(i)++)
#define rep(i,n) REP(i,0,n)
// BEGIN CUT HERE
#define foreach(itr,c) for(typeof((c).begin()) itr=(c).begin();itr!=(c).end();itr++)
template<class T> inline string toString(T x){ostringstream sout;sout<<x;return sout.str();}
// END CUT HERE

int main(){
  int i, j, n;
  int len1, len2;
  char tmp;

  scanf("%d",&n);
  rep(i,n){
    string str1, str2, res;
    cin >> str1;
    cin >> str2;

    vector<int> a(200, 0), b(200, 0);
    len1 = (int)str1.size(); len2 = (int)str2.size();
    rep(j,len1) a[j] = str1[(int)len1-1-j] - '0';
    rep(j,len2) b[j] = str2[(int)len2-1-j] - '0';

    rep(j,200){
      int sum = a[j] + b[j];
      if(sum >= 10){ sum %= 10; a[j+1]++;}
      res += (sum + '0');
    }

    reverse(res.begin(), res.end());
    int f = 0;
    rep(j,res.size()){
      if(res[j] != '0') f = 1;
      if(f && res.size()-j > 79){
        cout << "overflow" << endl;
        return 0;
      }
      if(f) cout << res[j];
    }

    cout << endl;
  }

  return 0;
}