int del(node *&root, node* x)
{
    node *p, *w;
    int k = x->val;
    if ((!x->left) || (!x->right))
        p = x;
        else
            p = next(x);
        if (p->left)
            w = p->left;
        else
            w = p->right;
        if (w)
            w->up = p->up;

        if (!p->up) root = w;
        else if (p == p->up->left) p->up->left = w;
        else p->up->right = w;
        if (p != x) x->val = p->val;

        delete p;
        return k;
}


void modify(node*& root_1, node*& root_2, node *x_2, int cond)
{
    if (x_2->val == cond)
    {
        add(root_1, del(root_2, next(x_2)));
    }
}