fn run<'a, F: FnMut() -> &'a str, W: std::io::Write>(scan: &mut F, writer: &mut W) {
    macro_rules! scan {
        ([$t:tt; $n:expr]) => ((0..$n).map(|_| scan!($t)).collect::<Vec<_>>());
        (($($t:tt),*)) => (($(scan!($t)),*));
        (Usize1) => (scan!(usize) - 1);
        (Bytes) => (scan().as_bytes().to_vec());
        ($t:ty) => (scan().parse::<$t>().unwrap());
    }
    macro_rules! println {
        ($($arg:tt)*) => (writeln!(writer, $($arg)*).ok());
    }

    let n = scan!(i32);

    println!("{}", if n & 1 == 0 { n / 2 + 1 } else { 1 });
}

fn main() {
    let ref mut buf = Vec::new();
    std::io::Read::read_to_end(&mut std::io::stdin(), buf).ok();
    let mut scanner = unsafe {
        std::str::from_utf8_unchecked(buf).split_ascii_whitespace()
    };
    let ref mut scan = || scanner.next().unwrap();

    let stdout = std::io::stdout();
    let ref mut writer = std::io::BufWriter::new(stdout.lock());

    run(scan, writer);
}