string compress(string s) {
    int n = s.size();
    int period = n;
    for (int l = 1; l <= n; l++) {
        bool good = true;
        string need = s.substr(0, l);
        int i = 0;
        while (i < n) {
            string cur = s.substr(i, l);
            for (int j = 0; j < min((int) cur.size(), l); j++) {
                if (cur[j] != need[j]) {
                    good = false;
                }
            }
            i += l;
        }
        if (good) {
            period = l;
            break;
        }
    }
    string rep = s.substr(0, period);
    return "(" + rep + ")";
}