import java.util.Scanner;
import java.math.BigInteger;

public class Main {
    public static void main(String[] args) {
    	Scanner sc = new Scanner(System.in);
    	
    	BigInteger biA = new BigInteger(sc.next());
    	BigInteger biB = new BigInteger(sc.next());
    	BigInteger biC = new BigInteger(sc.next());
    	BigInteger biD = new BigInteger(sc.next());
    	BigInteger biAns = new BigInteger("0");
    	
    	biAns = biAns.add(biA);
    	biAns = biAns.multiply(biB);
    	biAns = biAns.multiply(biC);
    	biAns = biAns.remainder(biD);
    	
    	System.out.println(biAns);
    }
}