// Следећи бинарни низ без суседних јединица
#include <iostream>
#include <string>
 
using namespace std;
 
int main()
{
    ios_base::sync_with_stdio(false);
    string binarni_niz;
    cin >> binarni_niz;
    int n = binarni_niz.length();
    int i = n - 1;
    while ((binarni_niz[i] == '1' and i >= 0) or (binarni_niz[i - 1] == '1' and i > 0))
    {
        binarni_niz[i] = '0';
        i--;
    }
    if (i < 0)
        cout << "ne postoji" << endl;
    else
    {
        binarni_niz[i] = '1';
        cout << binarni_niz << endl;
    }
    return 0;
}

Ly8g0KHQu9C10LTQtdGb0Lgg0LHQuNC90LDRgNC90Lgg0L3QuNC3INCx0LXQtyDRgdGD0YHQtdC00L3QuNGFINGY0LXQtNC40L3QuNGG0LAKI2luY2x1ZGUgPGlvc3RyZWFtPgojaW5jbHVkZSA8c3RyaW5nPgoKdXNpbmcgbmFtZXNwYWNlIHN0ZDsKCmludCBtYWluKCkKewogICAgaW9zX2Jhc2U6OnN5bmNfd2l0aF9zdGRpbyhmYWxzZSk7CiAgICBzdHJpbmcgYmluYXJuaV9uaXo7CiAgICBjaW4gPj4gYmluYXJuaV9uaXo7CiAgICBpbnQgbiA9IGJpbmFybmlfbml6Lmxlbmd0aCgpOwogICAgaW50IGkgPSBuIC0gMTsKICAgIHdoaWxlICgoYmluYXJuaV9uaXpbaV0gPT0gJzEnIGFuZCBpID49IDApIG9yIChiaW5hcm5pX25peltpIC0gMV0gPT0gJzEnIGFuZCBpID4gMCkpCiAgICB7CiAgICAgICAgYmluYXJuaV9uaXpbaV0gPSAnMCc7CiAgICAgICAgaS0tOwogICAgfQogICAgaWYgKGkgPCAwKQogICAgICAgIGNvdXQgPDwgIm5lIHBvc3RvamkiIDw8IGVuZGw7CiAgICBlbHNlCiAgICB7CiAgICAgICAgYmluYXJuaV9uaXpbaV0gPSAnMSc7CiAgICAgICAgY291dCA8PCBiaW5hcm5pX25peiA8PCBlbmRsOwogICAgfQogICAgcmV0dXJuIDA7Cn0=