if( $a ne "            " )
      {
      	 if( !exists $Hash{$a} )
      	 {
      	    $Hash{$a} = $b;
      	 }
      	 else
      	 {
      	    $is_there = 0;
      	    $tmp_is_there = 0;
      	    $temp = $Hash{$a};
      	    
            foreach my $elt ( @{$Hash{$a}} )
            {               
               if ($elt eq $b) 
               {
                  $is_there = 1;
               }
               if ($elt eq $temp) 
               {
                  $tmp_is_there = 1;               
               }
            }
                                    
            if ( !$is_there ) 
            {
            	push @{$Hash{$a}}, $b;   
            	
            }	    
            if ( !$tmp_is_there ) 
            {
            	push @{$Hash{$a}}, $temp;               	
            }	    
      	 }
      }