#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target( \
    "sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
using namespace std;
void itval(istream_iterator<string> it) {}
template <typename T, typename... Args>
void itval(istream_iterator<string> it, T a, Args... args) {
  cerr << *it << " = " << a << endl;
  itval(++it, args...);
}
const long long int MOD = 1e9 + 7;
template <typename T>
inline void print(T x) {
  cout << x << "\n";
}
template <typename T>
inline void printvec(T x) {
  for (auto a : x) cout << a << ' ';
  cout << '\n';
}
struct custom {
  bool operator()(const pair<int, pair<int, int> > &p1,
                  const pair<int, pair<int, int> > &p2) const {
    return p1.first < p2.first;
  }
};
long long int get_pow(long long int a, long long int b, long long int M = MOD) {
  long long int res = 1;
  while (b) {
    if (b & 1) res = (res * a) % M;
    a = (a * a) % M;
    b >>= 1;
  }
  return res;
}
const long long int N = 3e5 + 5, inf = 2e18;
void solve() {
  string s;
  cin >> s;
  int n = s.length();
  int q = 0, zero = 0, one = 0;
  for (auto c : s) {
    if (c == '1')
      one++;
    else if (c == '0')
      zero++;
    else
      q++;
  }
  if (q == 0) {
    if (zero >= one + 1) {
      cout << "00\n";
      return;
    } else if (one >= zero + 2) {
      cout << "11\n";
      return;
    } else {
      if (s.back() == '1')
        cout << "01\n";
      else
        cout << "10\n";
    }
    return;
  }
  int one_lim = q + one;
  set<string> ans;
  vector<int> pref(n, 0), p2(n, 0);
  for (long long int i = (long long int)0; i < (long long int)(n); i++) {
    if (s[i] != '0') pref[i]++;
    if (s[i] != '1') p2[i]++;
    if (i) {
      pref[i] += pref[i - 1];
      p2[i] += p2[i - 1];
    }
  }
  if (s.back() == '1') {
    for (long long int i = (long long int)one; i < (long long int)(one_lim + 1);
         i++) {
      int z = n - i;
      if (z >= 0) {
        if (z >= i + 1)
          ans.insert("00");
        else if (i >= z + 2)
          ans.insert("11");
        else {
          ans.insert("01");
        }
      }
    }
  } else if (s.back() == '0') {
    for (long long int i = (long long int)one; i < (long long int)(one_lim + 1);
         i++) {
      int z = n - i;
      if (z >= 0) {
        if (z >= i + 1)
          ans.insert("00");
        else if (i >= z + 2)
          ans.insert("11");
        else {
          ans.insert("10");
        }
      }
    }
  } else {
    one_lim--;
    zero++;
    for (long long int i = (long long int)one; i < (long long int)(one + q);
         i++) {
      int z = n - i;
      if (z >= 0) {
        if (z >= i + 1)
          ans.insert("00");
        else if (i >= z + 2)
          ans.insert("11");
        else {
          ans.insert("10");
        }
      }
    }
    zero--;
    one_lim++;
    one++;
    for (long long int i = (long long int)one; i < (long long int)(one + q);
         i++) {
      int z = n - i;
      if (z >= 0) {
        if (z >= i + 1)
          ans.insert("00");
        else if (i >= z + 2)
          ans.insert("11");
        else {
          ans.insert("01");
        }
      }
    }
  }
  for (auto p : ans) cout << p << '\n';
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  int test = 1;
  clock_t z = clock();
  for (long long int tes = (long long int)0; tes < (long long int)(test);
       tes++) {
    solve();
  }
  fprintf(stderr, "Total Time:%.4f\n", (double)(clock() - z) / CLOCKS_PER_SEC),
      fflush(stderr);
  return 0;
}
