#include <iostream>
#include <climits>
using namespace std;
const int MAX = 200000;
int N, M;
int v[MAX + 3];
int sp[MAX + 3];
int T, X, Y;
struct tree{
    int min, max, ans;
}aint[4 * MAX + 5];
int minn;
int sol;

void build(int nod, int st, int dr) {
    if(st == dr) {
        aint[nod].min = aint[nod].max = sp[st];
        aint[nod].ans = v[st];
        return;
    }
    int mid = (st + dr) / 2;
    build(2 * nod, st, mid);
    build(2 * nod + 1, mid + 1, dr);
    aint[nod].ans = max(max(aint[2 * nod].ans, aint[2 * nod + 1].ans), aint[2 * nod + 1].max - aint[2 * nod].min);
    aint[nod].max = max(aint[2 * nod].max, aint[2 * nod + 1].max);
    aint[nod].min = min(aint[2 * nod].min, aint[2 * nod + 1].min);
}

void query(int nod, int st, int dr, int x, int y) {
    if(x <= st && dr <= y) {
        sol = max(sol, max(aint[nod].ans, aint[nod].max - minn));
        minn = min(minn, aint[nod].min);
        return;
    }
    int mid = (st + dr) / 2;
    if(x <= mid) {
        query(2 * nod, st, mid, x, y);
    }
    if(y > mid) {
        query(2 * nod + 1, mid + 1, dr, x, y);
    }
}

int main() {
    freopen("sequencequery.in", "r", stdin);
    freopen("sequencequery.out", "w", stdout);
    cin >> N;cin >> M;
    for(int i = 1; i <= N; i++) {
        cin >> v[i];
        sp[i] = sp[i - 1] + v[i];
    }
    build(1, 1, N);
    
    for(int i = 1; i <= M; i++) {
        //cin >> T >> X >> Y;
        //if(T == 0) {
            //update
        //}
        //else {
            cin >> X >> Y;
            minn = INT_MAX / 2;
            sol = -INT_MAX / 2;
            query(1, 1, N, X, Y);
            cout << sol << '\n';
        //}
    }
}