string bydlocode = "a";

  for (int qq = 0; qq < 26; ++qq) {
    string a = bydlocode;
    bydlocode[0]++;
    bool ok = false;
    for (int i = 0; i < s.size(); ++i) {
      int q = a.size() - 1;
      a.push_back(a[q] + (s[i] == '=' ? 0 : s[i] == '>' ? - 1 : 1));
    }

    set<char> OMG_WHAT_ARE_YOU_DOING;
    for (int i = 0; i < a.size(); ++i) {
      OMG_WHAT_ARE_YOU_DOING.insert(a[i]);
      if (!islower(a[i]))
        ok = true;
    }
    if (ok || OMG_WHAT_ARE_YOU_DOING.size() > n || n > 26)
      continue;

    cout << a << endl;
    return 0;
  }