#include <bits/stdc++.h>

using namespace std;

string sumString(string a, string b) {
  if (a.size() > b.size()) swap(a, b);
  reverse(a.begin(), a.end());
  reverse(b.begin(), b.end());
  for (int i = 0; i < a.size(); i++) {
    if (a[i] + b[i] - 2 * '0' < 10) {
      b[i] += a[i] - '0';
    } else {
      b[i] = (a[i] + b[i] - 2 * '0') % 10 + '0';
      int j = i + 1;
      while (j < b.size() && b[j] == '9') {
        b[j++] = '0';
      }
      if (j == b.size()) b += "1";
      else b[j] += 1;
    }
  }
  reverse(b.begin(), b.end());
  return b;
}

int main(void) {
  int n;
  cin >> n;

  for (int i = 0; i < n; i++) {
    string a, b;
    cin >> a >> b;

    string ans = sumString(a, b);
    cout << (ans.size() <= 80 ? ans : "overflow") << endl;
  }

  return 0;
}
