#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  int a[13];
  for (int i = 0; i < 13; ++i) cin >> a[i];
  vector<int> cnt(10);
  for (int i = 0; i < 13; ++i) ++cnt[a[i]];
  vector<int> ans;
  for (int i = 1; i < 10; ++i)
  {
    ++cnt[i];
    int c3 = 0, c2 = 0;
    for (int j = 0; j < 10; ++j)
    {
      c2 += cnt[j] == 2;
      c3 += cnt[j] == 3;
    }
    if (c2 == 1 && c3 == 4) ans.push_back(i);
    --cnt[i];
  }
  cout << ans.size() << endl;
  for (auto v : ans) cout << v << ' ';
  cout << endl;
}