#include <iostream>
#include <string>

#define DIGIT  ( 80 )

using namespace std;

static
int N;

/** Application main entry point. */
int main (
  int     argc,
  char  * argv[ ]
  )
{
  cin >> N;

  while ( N-- )
  {
    string  A, B;
    int     C[ DIGIT + 1 ] = { 0 };

    cin >> A >> B;

    for ( size_t i = 0; i < A.length ( ); ++i )
    {
      C[ i ]      = A[ A.length ( ) - i - 1 ] - '0';
    }
    for ( size_t i = 0; i < B.length ( ); ++i )
    {
      C[ i ]     += B[ B.length ( ) - i - 1 ] - '0';
    }
    for ( size_t i = 0; i < DIGIT; ++i )
    {
      C[ i + 1 ] += C[ i ] / 10;
      C[ i ]     %= 10;
    }

    if ( C[ DIGIT ] )
    {
      cout << "overflow";
    }
    else
    {
      int i = DIGIT;
      while ( !C[ i ] && i > 0 )  --i;
      while ( i >= 0 )
      {
        cout << C[ i-- ];
      }
    }
    cout << endl;
  }

  return ( 0 );
}