#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 10;

int n, m, a[N];

struct val {
	int lm, rm, m, mk, l, r;
};

struct node {
	int l, r, lmo, rmo, num, flag, mz, mo, lmz, rmz;     //flag = 1: 全0    flag = 2: 全1     flag = 3:全反 
}tree[N * 4];

inline void update (int p, int op) {
	tree[p].flag = op;
	if (op == 1) {
		tree[p].num = tree[p].lmo = tree[p].rmo = tree[p].mo = 0;
		tree[p].lmz = tree[p].rmz = tree[p].mz = tree[p].r - tree[p].l + 1;
	}
	else if (op == 2) {
		tree[p].num = tree[p].lmo = tree[p].rmo = tree[p].mo = tree[p].r - tree[p].l + 1;
		tree[p].lmz = tree[p].rmz = tree[p].mz = 0;
	}
	else if (op == 3) {
		swap(tree[p].lmo, tree[p].lmz);
		swap(tree[p].rmo, tree[p].rmz);
		swap(tree[p].mo, tree[p].mz);
		tree[p].num = tree[p].r - tree[p].l + 1 - tree[p].num;
	}
}

inline void push_up(int p) {
	tree[p].num = tree[p * 2].num + tree[p * 2 + 1].num;
	tree[p].mo = max(max(tree[p * 2].mo, tree[p * 2 + 1].mo), tree[p * 2].lmo + tree[p * 2 + 1].rmo);
	tree[p].mz = max(max(tree[p * 2].mz, tree[p * 2 + 1].mz), tree[p * 2].lmz + tree[p * 2 + 1].rmz);
	
	if (tree[p * 2].rmo < tree[p * 2].r - tree[p * 2].l + 1) tree[p].rmo = tree[p * 2].rmo;
	else tree[p].rmo = tree[p * 2].rmo + tree[p * 2 + 1].rmo;
	if (tree[p * 2 + 1].lmo < tree[p * 2 + 1].r - tree[p * 2 + 1].l + 1) tree[p].lmo = tree[p * 2 + 1].lmo;
	else tree[p].lmo = tree[p * 2 + 1].lmo + tree[p * 2].lmo;
	
	if (tree[p * 2].rmz < tree[p * 2].r - tree[p * 2].l + 1) tree[p].rmz = tree[p * 2].rmz;
	else tree[p].rmz = tree[p * 2].rmz + tree[p * 2 + 1].rmz;
	if (tree[p * 2 + 1].lmz < tree[p * 2 + 1].r - tree[p * 2 + 1].l + 1) tree[p].lmz = tree[p * 2 + 1].lmz;
	else tree[p].lmz = tree[p * 2 + 1].lmz + tree[p * 2].lmz;
	
}

inline void push_down(int p) {
	update(p * 2, tree[p].flag); update(p * 2 + 1, tree[p].flag);
	tree[p].flag = 0;
}

void build (int p, int l, int r) {
	tree[p].l = l, tree[p].r = r;
	if (l == r) {
		if (a[l]) tree[p].lmo = tree[p].rmo = tree[p].mo = tree[p].num = 1;
		else tree[p].lmz = tree[p].rmz = tree[p].mz = 1;
		return;
	}
	int mid = (l + r) >> 1;
	if (l <= mid) build(p * 2, l, mid);
	if (r > mid) build(p * 2 + 1, mid + 1, r);
	push_up(p);
}

void add (int p, int l, int r, int op) {
	int tl = tree[p].l, tr = tree[p].r;
	if (tree[p].flag) push_down(p);
	if (tl >= l && tr <= r) {
		update(p, op);
		return;
	}
	int mid = (tl + tr) >> 1;
	if (l <= mid) add(p * 2, l, r, op);
	if (r > mid) add(p * 2 + 1, l, r, op);
	push_up(p);
}

int qp4 (int p, int l, int r) {
	int tl = tree[p].l, tr = tree[p].r;
	if (tree[p].flag) push_down(p);
	if (tl >= l && tr <= r) return tree[p].num;
	int mid = (tl + tr) >> 1, res = 0;
	if (l <= mid) res += qp4(p * 2, l, r);
	if (r > mid) res += qp4(p * 2 + 1, l, r);
	return res;
}

val qp5 (int p, int l, int r) {
	int tl = tree[p].l, tr = tree[p].r, lm = tree[p].lmo, rm = tree[p].rmo, m = tree[p].mo;
	if (tree[p].flag) push_down(p);
	if (tl >= l && tr <= r) return (val){lm, rm, m, 1, tl, tr};
	int mid = (tl + tr) >> 1;
	val a, b, c;
	a = b = c = (val){0, 0, 0, 0, 0, 0};
	c.mk = 1;
	if (l <= mid) a = qp5(p * 2, l, r);
	if (r > mid) b = qp5(p * 2 + 1, l, r);
	if (!b.mk) return a;
	if (!a.mk) return b;
	c.m = max(max(a.m, b.m), a.lm + b.rm);
	if (a.rm < a.r - a.l + 1) c.rm = a.rm;
	else c.rm = a.rm + b.rm;
	if (b.lm < b.r - b.l + 1) c.lm = b.lm;
	else c.lm = b.lm + a.lm;
	c.l = a.l, c.r = b.r;
	return c;
}

int main () {
	scanf("%d%d", &n, &m);
	for (int i = 1;i <= n;i++) scanf("%d", &a[i]);
	build(1, 1, n);
	while (m--) {
		int op, l, r;
		scanf("%d%d%d", &op, &l, &r);
		l++;r++;
		if (op <= 2) add(1, l, r, op + 1);
		else if (op == 3) printf("%d\n", qp4(1, l, r));
		else printf("%d\n", qp5(1, l, r).m);
	}
	return 0;
}

感觉思路没错，调出来几个bug还是不过