import java.io.*;
import java.util.*;

public class More {
  public static void main(String args[]) throws Exception {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    String line;
    while((line = in.readLine()) != null) {
	if(line.equals("11")){
	  System.out.println("0");
	  continue;	
	}
	char[] chars = line.toCharArray();
	boolean neg = true;
	for(int ti = 0; ti < chars.length; ti++) {
	  int i = chars.length - 1 - ti;
	  if(ti % 2 == 0){
	    if(chars[i] == '0'){
	      chars[i] = '1';
	      neg = false;
	      break;
            }else{
		chars[i] = '0';
	    }
          }else{
	        if(chars[i] == '1'){chars[i] = '0';}
		else{chars[i] = '1';}
            }
	}
	if(neg){
	  if(chars.length % 2 == 0){ // sude  - zaporne
		char[] chm = new char[chars.length];
		for(int i = 0; i < chars.length-2; i++){
			chm[i] = chars[i+2];		
		}
		System.out.println(new String(chm));
	  }else{
		System.out.println("11" + new String(chars));
	  }	
	}else{
		System.out.println(new String(chars));
	}
    }
  }
}