#include <boost/multiprecision/cpp_int.hpp>
#include <iostream>

int main() {
  using namespace std;
  namespace mp = boost::multiprecision;
  using Bint = mp::cpp_int;

  Bint UB = pow(Bint(10), 80);
  int n;
  cin >> n;
  while (n--) {
      Bint a, b;
      cin >> a >> b;
      Bint c = a + b;
      if (a >= UB || b >= UB || c >= UB) {
          cout << "overflow";
      } else {
          cout << c;
      }
      cout << endl;
  }
}

