struct p {
  int cnt = 0;
  int lp = 0;
};

string happyLadybugs(string b) {
  
  map<char, p> m;

  bool right = true;
  int pos = 0;
  for(auto& a : b) {
    m[a].cnt += 1;
    if(a != '_' && m[a].lp > 0 &&  m[a].lp != pos-1)
      right = false;
    m[a].lp = pos;
    pos++;
  }
  
  for(auto& a : m){
    if(a.first != '_' && a.second.cnt < 2) {
      return "NO";
    }
  }
  
  if(right)
    return "YES ";

  if(m.count('_') == 0)
    if(m.size() == 1 && (*m.begin()).second.cnt > 1)
      return "YES ";
    else
      return "NO";
  else {
    if(m.size() == 2 && 
       (*m.begin()).second.cnt + (*m.begin()++).second.cnt == b.size())
      return "YES ";
  }

  return "YES";
}