program xi;
type
as=array[1..1000000] of longint;
var a,b:as;
i,x,m:longint;
begin
read(m);
for i:=1 to m*2 do
a[i]:=i;x:=0;
repeat
for i:=1 to m do begin
b[i*2-1]:=a[i+m];b[i*2]:=a[i];end;x:=x+1;
if(b[1]<>1)and(b[2]<>2) then begin
for i:=1 to m do begin
a[i*2-1]:=b[i+m];a[i*2]:=b[i];end;x:=x+1;end;
until((a[1]=1)and(a[2]=2))or((b[1]=1)and(b[2]=2));
write(x);
end.