#include <cstring>
#include <iostream>
#include <cstdio>
#define FOR(i,a,b) for ( int i = int(a); i <= int(b); ++i )
#define FORD(i,a,b) for ( int i = int(a); i >= int(b); --i )
#define REP(i,n) for ( int i = 0; i < int(n); ++i )
using namespace std;

char res[1000014];


int main( ) {
	ios::sync_with_stdio( 0 );
  char c1,c2;
  for ( ;scanf(" %s", res+2) > 0;    memset(res, 0, sizeof(res)) ) {

    res[0] = res[1] = '0'; 
    int len = strlen(res); 

    if ( len == 3 && res[len-1] == '0' ) {
      cout << 1 <<endl;
      continue;
    } 

    if ( len&1) {
      if ( res[len-1] == '0' ) {
        res[len-1] = '1';
        cout << res+2 << endl;
        continue;   
      }  
      res[len-1] = '0';
      len--;       
      bool prenos = true;
      //cout << "kdasfkash"<<res <<endl;
      while ( prenos ) {
       // cout << "LEN" << len <<endl;       
        //break;
        c2 = res[len-1]; c1 = res[len-2];
        if (c1=='0' && c2 == '0' ) {
          res[len-2] = '1';
          res[len-1] = '1';
          prenos = false;  
        }
        else if (c1=='0' && c2 == '1' ) {
          res[len-2] = '0';
          res[len-1] = '0';
          prenos = false;  
        }
				else if (c1=='1' && c2 == '0' ) {
        //  cout << "dd"<<endl;
          res[len-2] = '0';
          res[len-1] = '1';
          prenos = true;  
        }
				else if (c1=='1' && c2 == '1' ) {
          res[len-2] = '1';
          res[len-1] = '0';
          prenos = false;  
        }
        len-=2; 
      }
   } else {
     bool prenos = true;
     while (prenos) {
        c2 = res[len-1]; c1 = res[len-2];
 				if (c1=='0' && c2 == '0' ) {
          res[len-2] = '0';
          res[len-1] = '1';
          prenos = false;  
        }
        if (c1=='0' && c2 == '1' ) {
          res[len-2] = '1';
          res[len-1] = '0';
          prenos = true;  
        }
				if (c1=='1' && c2 == '0' ) {
          res[len-2] = '1';
          res[len-1] = '1';
          prenos = false;  
        }
				if (c1=='1' && c2 == '1' ) {
          res[len-2] = '0';
          res[len-1] = '0';
          prenos = false;  
        }
        len-=2;            
     }
   }
   char * pc = res;
   bool first = true;
   while ( *pc ) {
     if ( *pc == '0' && first ) {
       pc++;
       continue;
     }
     first = false;
     cout << *pc++;
   }
   if ( first ) cout << 0;
     cout <<endl;
  }
	return 0;
}