PROGRAM SORTTEST(INPUT,OUTPUT);                   
 CONST N=16;                                      
 VAR A:ARRAY[1..N]OF INTEGER;                     
     P:TEXT;                                      
                                                  
 PROCEDURE GEN;                                   
  VAR I:INTEGER;                                  
      D:TEXT;                                     
 BEGIN                                            
  OPEN(D,8,3,"D,S,R");                            
  FOR I:=1 TO N DO READ(D,A[I]);                  
  CLOSE(D)                                        
 END;                                             
                                                  
 PROCEDURE OUT;                                   
  VAR I:INTEGER;                                  
 BEGIN                                            
  FOR I:=1 TO N DO WRITE(P,A[I]:3);               
  WRITELN(P);                                     
 END;                                             
                                                  
 PROCEDURE QUICK(L,R:INTEGER);                    
  VAR I,J,X,Y,Z:INTEGER;                          
 BEGIN                                            
  X:=A[(L+R)DIV 2];Y:=A[L];Z:=A[R];               
  WRITE(P,X,Y,Z);                                 
  IF X<Y THEN                                     
   BEGIN                                          
   IF X<Z THEN                                    
    IF Z<Y THEN X:=Z ELSE X:=Y                    
   END                                            
  ELSE                                            
   IF Z<X THEN                                    
    IF Z<Y THEN X:=Y ELSE X:=Z;                   
  WRITELN(P," MEDIAN:",X);                        
  I:=L;J:=R;                                      
  REPEAT                                          
   WHILE A[I]<X DO I:=I+1;                        
   WHILE A[J]>X DO J:=J-1;                        
   IF I<=J THEN                                   
    BEGIN                                         
     Y:=A[I];A[I]:=A[J];A[J]:=Y;                  
     I:=I+1;J:=J-1                                
    END;                                          
  UNTIL I>J;                                      
  OUT;                                            
  IF I<R THEN QUICK(I,R);                         
  IF L<J THEN QUICK(L,J);                         
 END;(*QUICK*)                                    
                                                  
BEGIN                                             
 OPEN(P,4,0,"");                                  
 GEN;OUT;QUICK(1,N);                              
 CLOSE(P)                                         
END.