#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAXL 2000000

char Buf[MAXL];
int Out[MAXL];

int main()
{
	while(gets(Buf))
	{
		int k = 0;
		int l = strlen(Buf);
		for(int i = l - 1; i >= 0; i--)
		{
			Out[k++] = Buf[i] - '0';
		}
		
		int last = k - 1;
		Out[k] = 0;
		Out[k + 1] = 0;
		
		for(int i = 0; 1; i++)
		{
			Out[i] ^= 1;
			if(i > last)
			{
				last = i;
			}
			
			if(Out[i] != i % 2)
			{
				break;
			}
		}
		
		int print = 0;
		for(int i = last; i >= 0; i--)
		{
			if(Out[i] == 1)
			{
				print = 1;
			}
			
			if(print)
			{
				printf("%d", Out[i]);
			}
		}
		
		if(!(print))
		{
			printf("0");
		}
		
		printf("\n");
	}
	
	return 0;
}