#include <algorithm>
#include <iostream>
#include <string>
#include <utility>
#include <vector>
using namespace std;

void stlip(vector<int> &v, string &s) {
  for (auto i = s.rbegin(), e = s.rend(); i != e; i++) {
    v.push_back(*i - 48);
  }
}

void print(vector<int> &v) {
  int n;
  string s;
  for (auto i = v.rbegin(), e = v.rend(); i != e; i++) {
    s += to_string(*i);
  }
  if (s.size() > 80)
    cout << "overflow" << endl;
  else
    cout << s << endl;
}

int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    vector<int> v1, v2, ret;
    string a, b;
    bool flag = true;
    cin >> a >> b;
    if (a.size() > 80 || b.size() > 80) {
      cout << "overflow" << endl;
      continue;
    }
    if (a.size() < b.size())
      swap(a, b);
    stlip(v1, a);
    stlip(v2, b);
    v2.resize(v1.size());
    for (int i = 0; i < v1.size(); i++) {
      int tmp;
      tmp = v1[i] + v2[i];
      if (tmp > 9) {
        if (i == v1.size() - 1) {
          v1.resize(v1.size() + 1);
          v2.resize(v1.size() + 1);
        }
        v2[i + 1] += 1;
        tmp -= 10;
      }
      ret.push_back(tmp);
    }
    if (flag)
      print(ret);
  }

  return 0;
}

