#include <iostream>
#include <vector>
using namespace std;
int main(){
  string s;cin>>s;s += "あ";
  //-17 -67 -105 
  string k = "";
  int tmp = 0;
  int mx = -1;
  vector<string> z;
  for(int i = 0; s.size()-2 > i; i+=3){
    if((int)s[i] == -17 && (int)s[i+1] == -67 && (int)s[i+2] == -105){
      tmp++;
    }else{
      if(tmp && k != ""){
        if(mx < tmp){
          z.clear();
          z.push_back(k);
          mx = tmp;
        }else if(mx == tmp){
          z.push_back(k);
        }
        k = s.substr(i,3);
      }else{
        k += s.substr(i,3);
      }
      tmp = 0;
    }
  }
  for(int i = 0; z.size() > i; i++){
    cout << z[i] << endl;
  }
}