fn main() {
    let mut input = String::new();
    std::io::stdin().read_line(&mut input).ok();
    let input: Vec<u64> = input
        .split_whitespace()
        .map(|n| n.parse().unwrap())
        .collect();

    let mut answer = input[0];
    answer %= input[3];
    answer *= input[1];
    answer %= input[3];
    answer *= input[2];
    answer %= input[3];

    println!("{}", answer);
}