Program Combinations;
Const max = 30;
Var x: Array[0..max] of Integer;
    n, k: Integer;
{In ra tập con {x1, x2, ..., xk)}
Procedure PrintResult;
Var i: Integer;
Begin
  Write('{');
  For i:= 1 To k - 1 Do Write(x[i], ', ');
  Writeln(x[k], '}');
End;
{Thử các cách chọn giá trị cho x[i]}
Procedure Try(i: Integer);
Var j: Integer;
Begin
  For j:= x[i-1] + 1 To n - k + i Do
  Begin
    x[i]:= j;
    If i = k Then PrintResult
    Else Try(i+1);
  End;
End;
Begin
  Assign(In, 'SUBSET.INP'); Reset(In);
  Assign(Out, 'SUBSET.OUT'); Rewrite(Out);
  Readln(n, k);
  x[0]:= 0;
  Try(1);
  Close(In);
  Close(Out);
End.

program lk_hoanvi;{liet ke cac hoan vi cua (1,2,3,...,n)}
const fi='lk_hoanvi.inp';
      fo='lk_hoanvi.out';
var n:integer;
    p:array[1..100] of integer;
    b:array[1..100] of boolean;
    dem: longint;
    f:text;
{==============init===============}
procedure init;
var i:integer;
begin
  assign(f,fi);reset(f);
  readln(f,n);close(f);
  for i:=1 to n do b[i]:=true;
  dem:=0;
  assign(f,fo);rewrite(f);
end;
{============ghinhan==============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem,'  :');
  for i:=1 to n do write(f,p[i]:3);
  writeln(f);
end;
{==============try================}
procedure try(i:integer);
var j:integer;
begin
  for j:=1 to n do
    if b[j] then {chap nhan j}
      begin
        p[i]:=j;
        b[j]:=false;
        if i=n then ghinhan
        else try(i+1);
        b[j]:=true;
      end;
end;
{===============main==============}
begin
  init;
  try(1);
  close(f);
end.

program lk_tohop;
const fi='lk_tohop.inp';
      fo='lk_tohop.out';
var n,k:integer;
    f:text;
    dem:longint;
    c:array[0..100] of integer;
{============init============}
procedure init;
begin
  assign(f,fi);reset(f);
  readln(f,k,n);close(f);
  dem:=0;
  c[0]:=0;
  assign(f,fo);rewrite(f);
end;
{===========ghinhan==========}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem:6,' :');
  for i:=1 to k do write(f,c[i]:3);
  writeln(f);
end;
{==========try===============}
procedure try(i:integer);
var j:integer;
begin

  for j:=c[i-1]+1 to n-k+i do
    begin
      c[i]:=j;
      if i=k then ghinhan
      else try(i+1);
    end;
end;
{============main============}
begin
  init;
  try(1);
  close(f);
end.

program lk_tapcon;{liet ke tapcon}
const fi='tapcon.inp';
      fo='tapcon.out';
      nmax=20;
var n:integer;
    b:array[1..nmax] of 0..1;
    dem:longint;
    f:text;
{=============init==============}
procedure init;
begin
  assign(f,fi);reset(f);
  readln(f,n);close(f);
  dem:=0;
  assign(f,fo);rewrite(f);
end;
{============ghinhan============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem:3,' :');
  for i:=1 to n do
    if b[i] <> 0 then write(f,i:3);
  writeln(f);
end;
{==============try==============}
procedure try(i:integer);
var j:integer;
begin
  for j:=0 to 1 do
    begin
      b[i]:=j;
      if i=n then ghinhan
      else try(i+1);
    end;
end;
{=============main==============}
begin
  init;
  try(1);
  close(f);
end.

program day_nhi_phan;{liet ke day nhi phan}
const fi='lknhiphan.inp';
      fo='lknhiphan.out';
var n:integer;
    b:array[1..20] of 0..1;
    dem:longint;
    f1,f2:text;
{=============init==============}
procedure init;
begin
  assign(f1,fi);reset(f1);
  assign(f2,fo);rewrite(f2);
  readln(f1,n);close(f1);
  dem:=0;
end;
{============ghinhan============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f2,dem,' :');
  for i:=1 to n do write(f2,b[i]);
  writeln(f2);
end;
{==============try==============}
procedure try(i:integer);
var j:integer;
begin
  for j:=0 to 1 do
    begin
      b[i]:=j;
      if i=n then ghinhan
      else try(i+1);
    end;
end;
{=============main==============}
begin
  init;
  try(1);
  close(f2);
end.

program xep_hau;
const n=8;
      fo='xephau.out';
var x: array[1..n] of byte;
    c:array[1..n] of boolean;
    cp:array[2..2*n] of boolean;
    cc:array[1-n..n-1] of boolean;
    dem:longint;
    f:text;
{==============init================}
procedure init;
begin
  assign(f,fo);rewrite(f);
  fillchar(c,sizeof(c),true);
  fillchar(cc,sizeof(cc),true);
  fillchar(cp,sizeof(cp),true);
  dem:=0;
end;
{=============ghinhan===============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem:3,' :');
  for i:=1 to n do write(f,x[i],' ');
  writeln(f);
end;
{================try================}
procedure try(i:integer);
var j:integer;
begin
  for j:=1 to n do
    if c[j]and cp[i+j] and cc[i-j] then
      begin
        x[i]:=j;
        c[j]:=false;cp[i+j]:=false;
        cc[i-j]:=false;
        if i=n then ghinhan
        else try(i+1);
        c[j]:=true;cp[i+j]:=true;
        cc[i-j]:=true;
      end;
end;
{===============main================}
begin
  init;
  try(1);
  close(f);
end.

program quan_xe;
const n=8;
      fo='quanxe.out';
var x: array[1..n] of byte;
    c:array[1..n] of boolean;
    dem:longint;
    f:text;
{==============init================}
procedure init;
begin
  assign(f,fo);rewrite(f);
  fillchar(c,sizeof(c),true);
  dem:=0;
end;
{=============ghinhan===============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem:3,' :');
  for i:=1 to n do write(f,x[i],' ');
  writeln(f);
end;
{================try================}
procedure try(i:integer);
var j:integer;
begin
  for j:=1 to n do
    if c[j] then
      begin
        x[i]:=j;
        c[j]:=false;
        if i=n then ghinhan
        else try(i+1);
        c[j]:=true;
      end;
end;
{===============main================}
begin
  init;
  try(1);
  close(f);
end.

program quan_tuong;
const n=8;
      fo='quantuong.out';
var x: array[1..n] of byte;
    cp:array[2..2*n] of boolean;
    cc:array[1-n..n-1] of boolean;
    dem:longint;
    f:text;
{==============init================}
procedure init;
begin
  assign(f,fo);rewrite(f);
  fillchar(cc,sizeof(cc),true);
  fillchar(cp,sizeof(cp),true);
  dem:=0;
end;
{=============ghinhan===============}
procedure ghinhan;
var i:integer;
begin
  inc(dem);
  write(f,dem:3,' :');
  for i:=1 to n do write(f,x[i],'  ');
  writeln(f);
end;
{================try================}
procedure try(i:integer);
var j:integer;
begin
  for j:=1 to n do
    if cp[i+j] and cc[i-j] then
      begin
        x[i]:=j;
        cp[i+j]:=false;
        cc[i-j]:=false;
        if i=n then ghinhan
        else try(i+1);
        cp[i+j]:=true;
        cc[i-j]:=true;
      end;
end;
{===============main================}
begin
  init;
  try(1);
  close(f);
end.