var
t: longint;
function f(x:longint): longint;
begin
if x = 0 then exit(0)
else if x mod 2 = 0 then exit(2 + f(x-1))
else exit(1 + f(x-1));
end;
begin
read(t);
writeln(f(t));
end.
输入:2014
输出：3021