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

int main()
{
	char *nega;
	char *vysl = malloc(100 * sizeof(char));
	
	while(scanf("%ms", &nega) == 1)
	{
		if (nega[strlen(nega) - 1] == '0')	
		{
			nega[strlen(nega) - 1] = '1';
			printf("%s\n", nega);
		}
		else
		{
			if (len % 2 == 0)
			{
				if (endsWith(01)
				{
					if (starts(11))
						substring(2);
					else
					{
						po dvojicich:
						
						10 -> 11
						11 -> 00
						00 -> 01
						01 -> 10
					}
				}
				else
				{
					10 -> 11
					11 -> 00
					00 -> 01
				}
			}
			else
			{
				
			}
		}
		
		a tak dale
		/*
		int i = 0, j = 0;
		long long res = 0;
		int len = strlen(nega);
		int pow = len - 1;
		for (i = 0; i < len; i++)
		{
			long long tmp = 1;
			for(j = 0; j < pow; j++)
			{
				tmp *= -2;
			}
			
			pow--;
			res += (nega[i] - '0') * tmp;
		}
		res++;
		
		int i = 0, j = 0;
		long long res = 0;
		int len = strlen(nega);
		int pow = len - 1;
		
		res = k;
		vysl[0] = '0';
		len = 0;
		
		int mod;
		while(res != 0)
		{
			mod = (res % 2 + 2) % 2;
			if(res > 0)
			{
				res = res / (-2);
			}
			else
			{
				res = res / (-2) + (mod ? 1 : 0);
			}
			vysl[len] = mod + '0';
			len++;
		}
	
		for(i = len - 1; i >= 0; i--)
		{
			printf("%c", vysl[i]);
		}
		if(len == 0) printf("0");
		printf("\n");
		*/
	}
	return 0;
}