#include <bits/stdc++.h>
#define INF 2e9
#define int long long
using namespace std;
#define ls(p) (p << 1)
#define rs(p) (p << 1 | 1)
int a[200005];
namespace sgt
{
    const int N = 2e5 + 5;
    struct node
    {
        int lmax, rmax, sum, maxn, tag = INF;
    } tree[N << 2];
    void pushup(int rt)
    {
        tree[rt].sum = tree[ls(rt)].sum + tree[rs(rt)].sum;
        tree[rt].lmax = max(tree[ls(rt)].lmax, tree[ls(rt)].sum + tree[rs(rt)].lmax);
        tree[rt].rmax = max(tree[rs(rt)].rmax, tree[rs(rt)].sum + tree[ls(rt)].rmax);
        tree[rt].maxn = max({tree[ls(rt)].maxn, tree[rs(rt)].maxn, tree[rs(rt)].lmax + tree[ls(rt)].rmax});
    }
    void addtag(int l, int r, int rt, int val)
    {
        tree[rt].tag += val;
        tree[rt].sum += (r - l + 1) * val;
        tree[rt].maxn = max(tree[rt].sum, 0ll);
        tree[rt].lmax = max(tree[rt].sum, 0ll);
        tree[rt].rmax = max(tree[rt].sum, 0ll);
    }
    void pushdown(int rt, int l, int r)
    {
        if (tree[rt].tag == INF)
            return;
        int mid = (l + r) >> 1;
        addtag(l, mid, ls(rt), tree[rt].tag);
        addtag(mid + 1, r, rs(rt), tree[rt].tag);
        // tree[ls(rt)].tag = tree[rs(rt)].tag = tree[rt].tag;
        tree[rt].tag = INF;
    }
    void build(int l, int r, int rt)
    {
        if (l == r)
        {
            tree[rt].sum = a[l];
            tree[rt].lmax = tree[rt].rmax = tree[rt].sum;
            tree[rt].maxn = max(tree[rt].sum, 0ll);
            return;
        }
        int mid = (l + r) >> 1;
        build(l, mid, ls(rt));
        build(mid + 1, r, rs(rt));
        pushup(rt);
    }
    void update(int l, int r, int rt, int L, int R, int val)
    {
        if (L <= l && r <= R)
        {
            addtag(l, r, rt, val);
            return;
        }
        pushdown(rt, l, r);
        int mid = (l + r) >> 1;
        if (L <= mid)
            update(l, mid, ls(rt), L, R, val);
        if (R > mid)
            update(mid + 1, r, rs(rt), L, R, val);
        pushup(rt);
    }
    int query(int l, int r, int rt, int L, int R)
    {
        if (L <= l && r <= R)
            return tree[rt].maxn;
        pushdown(rt, l, r);
        int mid = (l + r) >> 1, res = 0;
        if (L <= mid)
            res = max(res, query(l, mid, ls(rt), L, R));
        if (R > mid)
            res = max(res, query(mid + 1, r, rs(rt), L, R));
        return res;
    }
};
using namespace sgt;
signed main()
{
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
    }
    build(1, n, 1);
    while (m--)
    {
        int op, l, r, x;
        cin >> op >> l >> r;
        if (op == 1)
        {
            cin >> x;
            update(1, n, 1, l, r, x);
        }
        else
        {
            cout << query(1, n, 1, l, r) << endl;
        }
    }
    return 0;
}