import java.util.Scanner; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); long a = in.nextLong(); long b = in.nextLong(); long c = in.nextLong(); long d = in.nextLong(); System.out.println((a*b)%d*(c%d)); in.close(); } }