var a,b,c:longint;
begin
read(a);
if a mod 2=1 then write((a+1) div 2)
else begin b:=(a) div 2;c:=(a+2) div 2;write(b+c);end;
end.
/**************************************************************
	Problem: 1558
	User: admin
	Language: Pascal
	Result: Wrong Answer
****************************************************************/