import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

import static java.lang.System.in;

public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(in));
        String[] inputs = reader.readLine().split(" ");
        long A = Long.parseLong(inputs[0]);
        long B = Long.parseLong(inputs[1]);
        long C = Long.parseLong(inputs[2]);
        long D = Long.parseLong(inputs[3]);

        System.out.println((((A%D) * (B%D))%D * (C%D))%D);
    }
}