use std::io::Read;

fn main() {
    let mut buf = String::new();
    std::io::stdin().read_to_string(&mut buf).unwrap();
    let mut iter = buf.split_whitespace();

    let n: i32 = iter.next().unwrap().parse().unwrap();
    let k: i32 = iter.next().unwrap().parse().unwrap();

    let x = if n % 2 == 0 { n / 2 } else { n };

    if k % 2 == 0 {
        println!("{}", std::cmp::min(k + 1, x));
    } else {
        println!("{}", std::cmp::min((k + 1) / 2 * 2, x));
    }
}