/**
 *  American Computer Science League  Contest #1:  Intermediate Division
 */
package intermediate;

import java.io.*; // package contains BufferedReader class
import java.util.*; // package contains StringTokenizer class

/**
 * Given the length sides of two
 * @author gdonaldson
 *
 */
class Triangles                               // Intermediate Division
{
   public static void main( String[] args ) throws IOException
   {
      // Use BufferedReader to capture data from data file on disk drive
      BufferedReader in = new BufferedReader(
                          new FileReader( "TrianglesInter.in" ) );

      // == Read five lines containing six double tokens per line line. ==

      double AB=0, BC=0, AC=0, DE=0, EF=0, DF=0 ; 
      
      for( int i = 0; i < 5; i++ )
      {
         StringTokenizer st = new StringTokenizer( in.readLine() );
         AB = Double.parseDouble( st.nextToken() );
         BC = Double.parseDouble( st.nextToken() );
         AC = Double.parseDouble( st.nextToken() );
         DE = Double.parseDouble( st.nextToken() );
         EF = Double.parseDouble( st.nextToken() );
         DF = Double.parseDouble( st.nextToken() );   
         
         if      ( AB==DE && BC==EF && AC==DF) System.out.println("DEF");         
         else if ( AB==DE && BC==DF && AC==EF) System.out.println("EDF");
        
         else if ( AB==EF && BC==DE && AC==DF) System.out.println("FED");
         else if ( AB==EF && BC==DF && AC==DE) System.out.println("EFD");
        
         else if ( AB==DF && BC==DE && AC==EF) System.out.println("FDE");         
         else if ( AB==DF && BC==EF && AC==DE) System.out.println("DFE");
                          
         else System.out.println("NONE");

      } // end for
      
      System.exit( 0 ); // don't omit this

   } // end main()

} // end class Triangles [ Intermediate Division ]