#include <cstdio>
#include <string>
#include <vector>
#include <set>
#include <map>
#include <list>
#include <cstring>
#include <cmath>
#include <deque>
#include <algorithm>
#include <iostream>

using namespace std;

typedef long long int lint;
typedef long long ll;

void substract(string& pos, string const& neg, int len)
{
	int carry = 0;
	int i = 0;
	for (i = 0; i < len; ++i)
	{
		if (pos[i] >= neg[i] + carry)
		{
			pos[i] = pos[i] - (neg[i] + carry);
			carry = 0;
		}
		else
		{
			int n = neg[i] + carry;
			pos[i] = (n - pos[i]) % 2;
			carry = 1;			
		}
	}
	if (carry)
	{
		
	}
}

int main()
{
	string nb(1000000, 0);
	while (getline(cin, nb))
	{
		for (int i=0; i < nb.size(); ++i)
		{
			nb[i] -= '0';
		}
		reverse(nb.begin(), nb.end());
		nb.push_back(0);
		nb.push_back(0);
		nb.push_back(0);

		for (int i = 0; i < nb.size() - 1; ++i)
		{
			if (nb[i + 1] == 1 && nb[i] == 2) 
			{
				nb[i + 1] = 0;
				nb[i] = 0;
				break;
			}
			if ((i % 2) == 0)
			{
				if (nb[i] == 0) {
					nb[i] = 1;
					break;
				}
				else {
					nb[i] = 0;
					if (nb[i + 1] == 1)
					{
						nb[i + 1] = 0;
						break;
					}
					else continue;
				}
			}
			else
			{
				nb[i] = nb[i] + 1;
				nb[i + 1]++;
				if (nb[i] == 2 && nb[i + 1] == 1)
				{
					nb[i + 1] = 0;
					nb[i] = 0;
					break;
				}
				else if (nb[i] == 2 && nb[i + 1] == 2)
				{
					nb[i] = 0;
					nb[i + 1] = 1;
					break;
				}
				else if (nb[i] == 1 && nb[i + 1] == 1)
				{
					break;
				}
				else // (nb[i] == 1 && nb[i + 1] == 2)
				{
					//nb[i + 1] = 0;
					continue;
				}
			}
		}
		reverse(nb.begin(), nb.end());
		int i = 0; while (i < nb.size() && nb[i] == 0) ++i;
		if (i == nb.size()) 
		{
			printf("0\n");
			continue;		
		}
		for (; i < nb.size(); ++i)
		{
			printf("%c", nb[i] + '0');
		}
		printf("\n");		
	}
}