const fn gcd(a: u64, b: u64) -> u64 {
    let mut x = (a, b);
    while x.1 > 0 {
        x = (x.1, x.0 % x.1);
    }

    x.0
}

const fn lcm(a: u64, b: u64) -> u64 {
    a * b / gcd(a, b)
}

fn main() {
    let mut xx = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), &mut xx).ok();
    let xx: Vec<u64> = xx.split_whitespace().flat_map(str::parse).collect();

    println!(
        "{}",
        xx[0] / xx[1] + xx[0] / xx[2] + xx[0] / xx[3]
            - xx[0] / lcm(xx[1], xx[2])
            - xx[0] / lcm(xx[1], xx[3])
            - xx[0] / lcm(xx[2], xx[3])
            + xx[0] / lcm(lcm(xx[1], xx[2]), xx[3])
    );
}