#include <string>
#include <set>
#include <iostream>
using namespace std;

main()
{
  int i, j, k;
  string s;
  char tmp;
  set <string> all;
  set <string>::iterator ait;

  s.resize(10, ' ');
  for (i = 0; i < (1 << 10) ; i++) {
    for (j = 0; j < 10; j++) {
      if (i & (1 << j)) {
        s[j] = 'A';
      } else {
        s[j] = 'B';
      }
    }
    for (j = 0; j < 10; j++) {
      tmp = s[j];
      s[j] = 'C';
      all.insert(s);
      s[j] = tmp;
    }
  }
  
  for (ait = all.begin(); ait != all.end(); ait++) {
    cout << *ait << endl;
  }
}