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

int const SEED = 31415926;
int main() {
  int c;
  int count0, count1;
  srand(SEED);
  count0 = count1 = 0;
  while ((c = fgetc(stdin)) != EOF) {
    if (c == '0')
      count0++;
    else if (c == '1')
      count1++;
  }
  while (count0 > 0 || count1 > 0) {
    int f;
    f = (int)((double)rand() / ((double)RAND_MAX + 1) * (count0 + count1));
    if (f >= count0) {
      fputc('1', stdout);
      count1--;
    } else {
      fputc('0', stdout);
      count0--;
    }
  }
  return 0;
}
/* end */