What the 17 test? why WA?
armenia1993@mail.ru
int charact(int v) {
    used[v] = true;
    vector<int> dp;
    for (int i=0; i<g[v].size(); ++i) {
        int to = g[v][i];
        if (!used[to])
            dp.push_back(charact(to));
    }
        if (dp.size() == 0)
            return 0;
        sort(dp.begin(), dp.end());
        for (int i=dp.size(); i>0;--i)
            dp[i-1] += dp.size() - i + 1;
        return *max_element(dp.begin(), dp.end());
}