#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;

int main()
{
  int N;
  cin >> N;
  for(int i = 0; i < N; i++){
    char str1[81];
    char str2[81];
    string ans = "";
    cin >> str1;
    cin >> str2;
    int m1 = strlen(str1) - 1, m2 = strlen(str2) - 1, pre = 0;
    int m = max(m1, m2);
    if(m1 > 80 || m2 > 80)
      cout << "overflow" << endl;
    else if(atoi(str1) + atoi(str2) < 2147483600 && atoi(str1) + atoi(str2) > 0)
      cout << atoi(str1) + atoi(str2) << endl; 
    else{
      for(int j = 0; j <= m; j++){
	int sum = pre;
	sum += (m1 >= 0) ? str1[m1--] - '0' : 0;
	sum += (m2 >= 0) ? str2[m2--] - '0' : 0;
	pre = sum / 10;
	sum -= pre * 10;
	ans += '0' + sum;
      }
      if(pre > 0)
	ans += '0' + pre;
      reverse(ans.begin(), ans.end());
      if(ans.length() > 80)
	cout << "overflow" << endl;
      else
	cout << ans << endl;
    }
  }
}