#include <iostream>
#include <string>
using namespace std;

int main() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    string str1, str2, ans;
    cin >> str1 >> str2;
    int p1 = str1.length();
    int p2 = str2.length();
    int c = 0;
    while (p1 > 0 || p2 > 0) {
      int a = 0, b = 0;
      if (p1 > 0) {
        a = str1[--p1] - '0';
      }
      if (p2 > 0) {
        b = str2[--p2] - '0';
      }
      ans = to_string((a + b + c) % 10) + ans;
      c = (a + b + c) / 10;
    }
    if (c != 0) {
      ans = to_string(c) + ans;
    }
    if (ans.length() > 80) {
      cout << "overflow\n";
    } else {
      cout << ans << "\n";
    }
  }
  return 0;
}
