#include <iostream>
#include <string>
using namespace std;
int main( void )
{
  int n;
  string s1,s2;
  int d1[82],d2[82],d3[82];
  cin >> n;
  for( int k=0; k<n; k++ ){
    cin >> s1 >> s2;
    if( s1.size() > 80 || s2.size() > 80 ){
      cout << "overflow" << endl;
      continue;
    }
    for( int i=0; i<s1.size(); i++ ) d1[i] = s1[s1.size()-i-1] - '0';
    for( int i=s1.size(); i<80; i++ ) d1[i] = 0;
    for( int i=0; i<s2.size(); i++ ) d2[i] = s2[s2.size()-i-1] - '0';
    for( int i=s2.size(); i<80; i++ ) d2[i] = 0;
    for( int i=0; i<=80; i++ ) d3[i] = 0;
    for( int i=0; i<80; i++ ){
      d3[i] += d1[i] + d2[i];
      if( d3[i] >= 10 ){ d3[i] %= 10; d3[i+1]++; }
    }
    int i=80;
    if( d3[i] > 0 ){
      cout << "overflow" << endl;
      continue;
    }
    while( d3[--i] == 0 )
      ;
    while( i >= 0 ) cout << d3[i--];
    cout << endl;
  }
  return 0;
}