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

using namespace std;

int main(int argc, char *argv[]) {
  int n;
  vector<string> result;
  string a, b;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> a >> b;
    if (a.size() > 80 || b.size() > 80) {
      result.push_back("overflow");
      continue;
    }

    int carry = 0;
    if (a.size() < b.size())
      a.swap(b);
    string::reverse_iterator ria = a.rbegin();
    string::reverse_iterator rib = b.rbegin();

    while (true) {
      if (*ria - '0' + *rib - '0' + carry >= 10) {
        *ria += *rib + carry - '0' - 10;
        carry = 1;
      } else {
        *ria += *rib + carry - '0';
        carry = 0;
      }
      ria++;
      rib++;
      if (rib == b.rend())
        break;
    }
    /*                                                                                                                                                                                                                                                         
    cout << a << endl;                                                                                                                                                                                                                                         
    cout << carry << endl;                                                                                                                                                                                                                                     
    */
    while (true) {
      if (carry && ria == a.rend())
        a.insert(0, "1");
      else if (carry)
        if (*ria - '0' + 1 >= 10) {
          *ria += carry - 10;
          carry = 1;
        } else {
          *ria += 1;
          carry = 0;
          break;
        }
      else
        break;
      ria++;
    }
    if (a.size() > 80)
      result.push_back("overflow");
    else
      result.push_back(a);
  }

  for (int i = 0; i < result.size(); i++)
    cout << result[i] << endl;
  return 0;
}