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

char line[2000000];
int dlzka;
int prenos;
bool opakuj;

char xoruj(char x) {
	if (x == '0') return '1';
	if (x == '1') return '0';
	return x;
}

int main() {
	while( scanf("%s", line + 2) >=1) {
		opakuj = true;
		prenos = 1;

		line[0] = '0';
		line[1] = '0';

		dlzka = strlen(line);
		dlzka--;

		while (opakuj) {
			if (prenos == -1 && line[dlzka] == '1') {
					opakuj = false;
				}
			if (prenos == 1 && line[dlzka] == '0') {
					opakuj = false;
				}

			line[dlzka] = xoruj(line[dlzka]);
			dlzka--; prenos *= -1;
		}
		
		int i = 0;
		for (i = 0; line[i] != '\0'; i++) {
			if (line[i] == '1') break;
		}
		if (line[i] == '\0') {
			printf("0\n");
		} else {
			printf("%s\n",line+i);
		}
	}
  
  return 0;
}