#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
int main() {
  int N;
  cin >> N;
  for (int i = 0; i < N; i++) {
    char a[1000];
    char b[1000];
    char sum[1000];
    scanf("%s\n", a);
    scanf("%s\n", b);
    if (strlen(a) > 80 || strlen(b) > 80) {
      cout << "overflow" << endl;
      continue;
    }
    int c = 0;
    int al = strlen(a);
    int bl = strlen(b);
    for (int i = 0; i < max(al, bl); i++) {
      int da, db;
      if (al-i-1>=0) da = a[al-i-1] - '0';
      else da = 0;
      if (bl-i-1>=0) db = b[bl-i-1] - '0';
      else db = 0;
      int s = da + db + c;
      if (s >= 10) {
        s -= 10;
        c = 1;
      } else {
        c = 0;
      }
      sum[i] = s + '0';
    }

    if ((al == 80 || bl == 80) && c == 1) {
      cout << "overflow" << endl;
      continue;
    }

    if (c == 1) cout << '1';
    for (int i = max(al, bl) - 1; i >= 0; i--) {
      cout << sum[i];
    }
    cout << endl;
  }
  return 0;
}