#include <cmath>
#include <cstdlib>
#include <cstdio>

#include <iostream>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>



int main() {

  std::string a, b;
  long x[81] = {};
  long y[81] = {};
  long N;
  char temp;
  long len;

  std::cin >> N;
  for(int i = 0; i < N; ++i) {
    std::cin >> a >> b;
    for(int j = 0; j < 81; ++j) {
      x[j] = y[j] = 0;
    }
    for(int j = 0; j < a.size(); ++j) x[j] = a[ a.size()-j-1 ] - '0';
    for(int j = 0; j < b.size(); ++j) y[j] = b[ b.size()-j-1 ] - '0';

    temp = 0;
    for(int j = 0; j < 81; ++j) {
      temp = x[j] + y[j] + temp;
      x[j] = (temp % 10);
      temp /= 10;
    }

    len = std::max(a.size(), b.size());
    if( x[len] != 0 ) {
      if( len == 80 ) { 
	std::cout << "overflow" << std::endl;
	continue;
      }
      for(int j = len; j >= 0; --j) {
	std::cout << x[j];
      }
      std::cout << std::endl;
      continue;
    }
    for(int j = len-1; j >= 0; --j) {
      std::cout << x[j];
    }
    std::cout << std::endl;
  }
    
  return 0;
}