#include <iostream>
#include <fstream>

#define NMAX 100003

using namespace std;

typedef long long ll;

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

struct Node {
    ll sum, pref_smax, suff_smax, smax;
} tree[4 * NMAX];

ll N, M, a[NMAX];



Node update(Node le, Node ri) {
    Node curr;

    curr.sum = le.sum + ri.sum;

    curr.pref_smax = max(le.pref_smax, le.sum + ri.pref_smax);
    curr.suff_smax = max(ri.suff_smax, ri.sum + le.suff_smax);

    curr.smax = max(le.suff_smax + ri.pref_smax, max(le.smax, ri.smax));

    return curr;
}

void build(int nod, int le, int ri) {
    if (le == ri) {
        tree[nod].sum = a[le];
        tree[nod].pref_smax = a[le];
        tree[nod].suff_smax = a[le];
        tree[nod].smax = a[le];
        return;
    }

    int mid = (le + ri) / 2;
    build(2 * nod, le, mid);
    build(2 * nod + 1, mid + 1, ri);

    tree[nod] = update(tree[2 * nod], tree[2 * nod + 1]);
}

Node query(int nod, int le, int ri, int ql, int qr) {
    if (ql <= le && ri <= qr) {
        return tree[nod];
    }

    int mid = (le + ri) / 2;
    if (qr <= mid)
        return query(2 * nod, le, mid, ql, qr);
    if (mid + 1 <= ql)
        return query(2 * nod + 1, mid + 1, ri, ql, qr);

    return update(query(2 * nod, le, mid, ql, qr), query(2 * nod + 1, mid + 1, ri, ql, qr));
}

int main() {

    ios::sync_with_stdio(false);

    fin >> N >> M;
    for (int i = 1; i <= N; i++)
        fin >> a[i];
    build(1, 1, N);

    for (int q = 0; q < M; q++) {
        int x, y;
        fin >> x >> y;
        fout << query(1, 1, N, x, y).smax << '\n';
    }


    return 0;
}