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

#define int long long

ifstream fin("sequencequery.in");
ofstream fout("sequencequery.out");

const int LMAX = 1e5 + 7;
const int INF = 2e18;

struct Vec
{
    int sum = -INF;
    int ans = -INF;
    int pref = -INF;
    int suf = -INF;
} aint[4 * LMAX];

int n, m;
int v[LMAX];

Vec combinare(Vec a, Vec b)
{
    Vec x;
    x.sum = a.sum + b.sum;
    x.pref = max(a.pref, b.pref + a.sum);
    x.suf = max(b.suf, b.sum + a.suf);
    x.ans = max(max(a.ans, b.ans), a.suf + b.pref);
    return x;
}

void build(int nod, int l, int r)
{
    if (l == r)
    {
        aint[nod].ans = v[l];
        aint[nod].sum = v[l];
        aint[nod].pref = v[l];
        aint[nod].suf = v[l];
        return;
    }

    int mid = (l + r) / 2;

    build(nod * 2, l, mid);
    build(nod * 2 + 1, mid + 1, r);

    aint[nod] = combinare(aint[nod * 2], aint[nod * 2 + 1]);
    //fout << nod << ": " << l << " " << r << " " << aint[nod].sum << " " << aint[nod].pref << " " << aint[nod].suf << " " << aint[nod].ans << "\n";
}

Vec query(int nod, int l, int r, int x, int y)
{
    if (x <= l && r <= y)
    {
        return aint[nod];
    }

    int mid = (l + r) / 2;

    Vec a, b;

    if (x <= mid)
    {
        a = query(nod * 2, l, mid, x, y);
    }
    if (y > mid)
    {
        b = query(nod * 2 + 1, mid + 1, r, x, y);
    }

    Vec aux = combinare(a, b);

    return combinare(a, b);
}

 main()
{
    fin >> n >> m;
    for (int i = 1; i <= n; i++)
    {
        fin >> v[i];
    }

    build(1, 1, n);

    for (int i = 1; i <= m; i++)
    {
        int a, b;
        fin >> a >> b;
        Vec ans = query(1, 1, n, a, b);
        fout << ans.ans << "\n";
    }
    return 0;
}