procedure generate(k: integer);
var
    j, t: integer;
procedure print(var a: arr);
var
    i: integer;
begin
    for i := 1 to n do
        write(a[i], ' ');
    writeln;
end;
begin
    if k = 1 then
        print(a)
    else begin
        generate(k-1);
        for j := 1 to k - 1 do begin
            t := a[j];
            a[j] := a[k];
            a[k] := t;
            generate(k-1);
        end;

    end;
end;