import java.util.Scanner;
public class TGMain {
    
    public static void main(String[] args){
        int a, b, c, N;
        int ans = 0;
        Scanner sc = new Scanner(System.in);
        a = sc.nextInt();
        b = sc.nextInt();
        c = sc.nextInt();
        N = sc.nextInt();
        ans = a*b*c;
        ans = ans%N;
        System.out.println(ans);
    }
}