var
 S:string;
 i,j,N,m: integer;
 W:Array[1..255] of String;
 Q:Set of byte;
begin
 writeln('Enter the string: ');
 readln(S);
 N:=1;
 i:=1;
 Repeat
  While (S[i]=' ') and (i<Length(S)) do Inc(i);
  W[N]:='';
  While (S[i]<>' ') and (i<=Length(S)) do
   begin
    W[N]:=W[N]+S[i];
    Inc(i);
   end;
  If i<Length(S) then Inc(N);
 Until i>=Length(S);
 Q:=[];
 For i:=1 to N do
  begin
   If Not(i in Q) then
    begin
     Q:=Q+[i];
     m:=0;
     for j:=i to N do
      if W[i]=W[j] then
       begin
        Q:=Q+[j];
        Inc(m);
       end;
     If m<3 then write(W[i]+' ');
    end;
  end;
 Readln
End.