fn main() {
    let mut abcd = String::new();
    std::io::stdin().read_line(&mut abcd).ok();
    let abcd: Vec<u128> = abcd.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let a = abcd[0];
    let b = abcd[1];
    let c = abcd[2];
    let d = abcd[3];

    println!("{}", a * b * c % d);
}