bool check(vector <int> a){
    int v = 0, i, j;
    bool temp = 0;
    vector <bool> bol(a.size());
    for (int i = 0; i < a.size(); i++)
        bol[i] = 1;

    for (int i = 0; i < a.size(); i++)
        if (bol[i]){
            v = 0;
            j = i;
            while (bol[j]){
                v++;
                bol[j] = 0;
                j = a[j];
            }
            temp = temp || v % 2;
        }

    cout << temp << endl;
    return temp;
}