fn main() {
    let mut xx = String::new();
    std::io::stdin().read_line(&mut xx).ok();
    let xx: Vec<i64> = xx.split_whitespace().flat_map(str::parse).collect();

    let (mut n, m, p, q) = (xx[0], xx[1], xx[2], xx[3]);

    let drop: Vec<i64> = (1..=12)
        .map(|i| if i >= p && i < p + q { 2 * m } else { m })
        .scan(0, |acc, x| {
            *acc += x;
            Some(*acc)
        })
        .collect();

    let yy = n / drop[11];
    n %= drop[11];

    let mm = drop.iter().position(|&i| n <= i).unwrap() as i64 + 1;

    println!("{}", 12 * yy + mm);
}