pain

struct segtree {
    struct node {
        int v, d = -1;
    };

    vector <node> tree;

    void init(const vector <int>& v) {
        tree.resize(2 * R);
        FOR1(0, v.size()) tree[R + i].v = v[i];
        RFOR(R - 1, 1) tree[l].v = tree[l * 2].v + tree[l * 2 + 1].v;
    }

    int cnt(int len, int node) {
        if (tree[node].d == 0) return len - tree[node].v;
        if (tree[node].d == 1) return tree[node].v;
        if (tree[node].d == 2) return 0;
        if (tree[node].d == 3) return len;
    }

    void push(int node, int len) {
        if (tree[node].d == -1) return;
        tree[node * 2].d = tree[node].d;
        tree[node * 2].v = cnt(len >> 1, node * 2);
        tree[node * 2 + 1].d = tree[node].d;
        tree[node * 2 + 1].v = cnt(len >> 1, node * 2 + 1);
        tree[node].d = -1;
    }

    void upd(int ql, int qr, int val, int node = 1, int nl = 0, int nr = R) {
        if (qr <= nl || nr <= ql) return;
        if (ql <= nl && nr <= qr) {
            tree[node].d = val;
            tree[node].v = cnt(nr - nl, node);
            return;
        }
        push(node, nr - nl);
        int nm = (nl + nr) >> 1;
        upd(ql, qr, val, node * 2, nl, nm);
        upd(ql, qr, val, node * 2 + 1, nm, nr);
        tree[node].v = tree[node * 2].v + tree[node * 2 + 1].v;
    }

    int rsq(int ql, int qr, int node = 1, int nl = 0, int nr = R) {
        if (qr <= nl || nr <= ql) return 0;
        if (ql <= nl && nr <= qr) return tree[node].v;
        push(node, nr - nl);
        int nm = (nl + nr) >> 1;
        return rsq(ql, qr, node * 2, nl, nm) + rsq(ql, qr, node * 2 + 1, nm, nr);
    }
};