void rec(string now, vector<int> have){

    if(have.size() == 0){
        cout << now;
        return;
    }

    for(int i = 0; i <= 'z' - 'a'; i++){
        if(have[i] > 0){
            have[i]--;
            rec(now + (char)('a'+i), have);
            have[i]++;
        }
    }

}