2015-02

void removeDuplicateAndSort(string& s)
{
    if (s.length() == 0) return;
    sort(s.begin(),s.end());

    for (int i = 1; i < s.length(); i++)
    {
        if (s[i] == s[i - 1])
        {
            s.erase(i, 1);
            i--;
        }
    }
}

int main()
{
    string s = "";

    cin >> s;

    removeDuplicateAndSort(s);

    cout << s << endl;

    return 0;
}