#include "bits/stdc++.h"
using namespace std;

#define int long long
#define root tr[u]
#define left tr[u << 1]
#define right tr[u << 1 ^ 1]

const int N = 1e6 + 5;

int c[N];
int n, q;

struct Node
{
    int l, r;
    int max;
    int add = 0, mul = 1;
}tr[N * 4];

void pushup(int u)
{
    root.max = max(left.max, right.max);
}

void pushdown(int u)
{
    if (root.mul != 1)
    {
        left.mul *= root.mul;
        left.max *= root.mul;
        right.mul *= root.mul;
        right.max *= root.mul;
        root.mul = 1;
    }
    if (root.add)
    {
        left.add += root.add;
        left.max += root.add;
        right.add += root.add;
        right.max += root.add;
        root.add = 0;
    }
}

void build(int u, int l, int r)
{
    if (l == r)
    {
        root = {l, r, c[l]};
        return;
    }
    
    root = {l, r};
    int mid = l + r >> 1;
    build(u << 1, l, mid), build(u << 1 ^ 1, mid + 1, r);
    pushup(u);
}

void modify(int u, int l, int r, int mul, int add)
{
    if (root.l >= l && root.r <= r)
    {
        root.max = root.max * mul + add;
        root.add += add;
        root.mul *= mul;
        // pushdown(u);
    }
    else
    {
        int mid = root.l + root.r >> 1;
        pushdown(u);
        if (l <= mid) modify(u << 1, l, r, mul, add);
        if (r > mid) modify(u << 1 ^ 1, l, r, mul, add);
        pushup(u);
    }
}

int query(int u, int l, int r)
{
    if (root.l >= l && root.r <= r)
        return root.max;
    
    int mid = root.l + root.r >> 1;
    int res = -0x3f3f3f3f;
    pushdown(u);
    if (l <= mid) res = query(u << 1, l, r);
    if (r > mid) res = max(query(u << 1 ^ 1, l, r), res);
    return res;
}

void test()
{
    // cout << "\t";
    // for (int i = 1; i <= n; ++i)
    //     cout << query(1, i, i) << " ";
    // cout << endl;
}

signed main()
{
    scanf("%lld%lld", &n, &q);
    for (int i = 1; i <= n; ++i) scanf("%lld", &c[i]);
    build(1, 1, n);
    test();
    while (q --)
    {
        int a, l, r;
        scanf("%lld%lld%lld", &a, &l ,&r);
        if (r < l) swap(l, r);
        if (a == 1)
        {
            int x;
            scanf("%lld", &x);
            modify(1, l, r, 0, x);
        }
        else if (a == 2)
        {
            int x;
            scanf("%lld", &x);
            modify(1, l, r, 1, x);
        }
        else
            printf("%lld\n", query(1, l, r));

        test();
    }
    return 0;
}