import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int x = sc.nextInt();
		int y =x%10*1000+x/10%10*100+x/100%10*10+x/1000%10;
		System.out.println(x-y);
	}

}
/**************************************************************
	Problem: 1702
	User: admin
	Language: Java
	Result: Accepted
	Time:647 ms
	Memory:39964 kb
****************************************************************/