#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
int main()
{
    int i;
    int countzero=0;
    int countone=0;
    char c;

    while (EOF != (c = getchar()))
    {
        if(c=='0')
            countzero++;
        else if(c=='1')
            countone++;
        else
            break;
    }
    int* ptr;
    ptr=(int *)malloc((countzero+countone)*sizeof(int));
    i=0;
    while(i<countzero+countone)
    {
        if(i<countzero)
            ptr[i]=0;
        else
            ptr[i]=1;
    }
    i=0;
    for(i=0;i<(countzero+countone);i++)
        printf("%d", ptr[i]);
}