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

int main() {
  int N;
  cin >> N;
  for (int n = 0; n < N; ++n) {
    string A, B;
    cin >> A >> B;

    int A_size = A.size(), B_size = B.size(),
        ans_size = max(A_size, B_size) + 1;
    vector<int> ans(ans_size);
    for (int i = A_size - 1; i >= 0; --i)
      ans[ans_size - A_size + i] = A[i] - '0';
    for (int j = B_size - 1; j >= 0; --j) {
      ans[ans_size - B_size + j] += B[j] - '0';
      for (int k = ans_size - 1; k > 0; --k)
        if (ans[k] >= 10)
          ans[k] -= 10, ++ans[k - 1];
    }

    if (A_size > 80 || B_size > 80 || (ans_size == 81 && ans[0] != 0) ||
        ans_size > 81) {
      cout << "overflow" << endl;
    } else {
      for (int i = 0; i < ans_size; ++i) {
        if (i == 0 && ans[i] == 0)
          continue;
        cout << ans[i];
      }
      cout << endl;
    }
  }
}
