#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <string>
#include <sstream>
#include <iostream>

#define REP(i, cnt) for (int i = 0; i < (cnt); i++)

using namespace std;
typedef long long int64;

string rev(const string &str) {
	string out = str;
	REP(i, str.length())
		out[i] = str[str.length()-i-1];
	return out;
}

int main() {
	string input;
	string reverse;
	while (getline(cin, input)) {
		reverse = rev(input);
		bool done = false;
		int sign = 1;
		for (int j = 0; j < reverse.length(); j++) {
			int bit = reverse[j]-'0';
			reverse[j] = '0'+!bit;
			if ((sign < 0 && bit) || (sign > 0 && !bit)) {
				done = true;
				break;
			}
			sign *= -1;
		}
		while (!done) {
			int bit = 0;
			reverse += '1';
			if ((sign < 0 && bit) || (sign > 0 && !bit)) {
				done = true;
				break;
			}
			sign *= -1;
		}
		int len = reverse.length();
		for (int j = reverse.length()-1; j > 0; j--) {
			if (reverse[j] == '0')
				len--;
			else
				break;
		}
		cout << rev(reverse.substr(0, len)) << endl;
	}
	return 0;
}