Const
 Nmax=12;
Var
 N,i,j,j1,j2,k:Byte;
 sj:ShortInt;
 A:Array[1..Nmax,1..Nmax] of Byte;

Begin
 Write('N (<',Nmax+1,') = ');
 Readln(N);
 Writeln;
 k:=0;
 sj:=1;
 for i:=1 to N do
  for j:=1 to N do
   A[i,j]:=0;
 i:=1;
 Repeat
  j1:=i;
  j2:=N-i+1;
  if sj=1 then
   for j:=j1 to j2 do
    begin
     k:=k+1;
     A[i,j]:=k;
    end
  else
   for j:=j2 downto j1 do
    begin
     k:=k+1;
     A[i,j]:=k;
    end;
  sj:=-sj;
  i:=i+1;
 Until i>N-i+1;
 Repeat
  j1:=N-i+1;
  j2:=i;
  if sj=1 then
   for j:=j1 to j2 do
    begin
     k:=k+1;
     A[i,j]:=k;
    end
  else
   for j:=j2 downto j1 do
    begin
     k:=k+1;
     A[i,j]:=k;
    end;
  sj:=-sj;
  i:=i+1;
 Until i=N+1;
 for i:=1 to N do
  begin
   for j:=1 to N do Write(A[i,j]:5);
   writeln;
  end;
 Readln
End.