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


void add1(char *num) {
	int length = strlen(num);
	int i, carry = 0;
	
	if (length % 2 == 0) {
		if (num[length-1] == '0') num[length-1] = '1';
		else {
			for (i = length-1; i >= 2; i--) {
				if (i == length - 1) carry = 1;
				if ((length - 1 - i) % 2 == 1) {
					if (num[i] == '1') {
						if (carry) {
							num[i]= '0';
							carry = 0;
						}
						else {
							carry = 1;
						}
					}
					else {
						if (carry) {
							num[i] = '1';
							carry = 1;
						}
						else carry = 0;
					}
				}
				else {
					if (num[i] == '1') {
						if (carry) {
							num[i]= '0';
							carry = 1;
						}
						else {
							carry = 0;
						}
					}
					else {
						if (carry) {
							num[i] = '1';
							carry = 0;
						}
						else carry = 0;
					}
				}
			}
		}
	}
	else {
		for (i = length-1; i >= 0; i--) {
			if (i == length - 1) carry = 1;
			if ((length - 1 - i) % 2 == 1) {
				if (num[i] == '1') {
					if (carry) {
						num[i]= '0';
						carry = 1;
					}
					else {
						carry = 0;
					}
				}
				else {
					if (carry) {
						num[i] = '1';
						carry = 0;
					}
					else carry = 0;
				}
				if (num[i] == '1') carry = 1;
			}
			else {
				if (num[i] == '1') {
					if (carry) {
						num[i]= '0';
						carry = 1;
					}
					else {
						carry = 0;
					}
				}
				else {
					if (carry) {
						num[i] = '1';
						carry = 0;
					}
					else carry = 0;
				}
			}
		}
	}
}

int main() {
	char str[1000005];
	while (scanf("%s", str+2) > 0) {
		int i = 0;
		str[0] = '0';
		str[1] = '0';
		add1(str);
		while (str[i] == '0' && str[i] != 0) i++;
		if (str[i] == 0) printf("0\n");
		else printf("%s\n", str + i);
	}

	return 0;
}