var a: array [1..100] of integer; i, n, k: integer;begin readln(k); n := (k * 2) - 1; A[1] := 1; write(A[1], ' '); for i := 2 to k do begin A[i] := A[i - 1] + 1; write(A[i], ' '); end; for i := k + 1 to n do begin A[i] := A[i - 1] - 1; write(A[i], ' '); end;end.0