#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream fin("sequencequery.in");
ofstream fout("sequencequery.out");

const int nmax = 100000;
int n;

struct NODE
{
    long long best = 0;
    long long suf = 0;
    long long pref = 0;
    long long tot = 0;
} a[nmax * 4 + 5];

NODE best(NODE a,NODE b)
{
    NODE c = {0,0,0,0};
    c.pref = max(a.pref,a.tot + b.pref);
    c.suf = max(b.suf,b.tot + a.suf);
    c.best = max(c.pref,c.suf);
    c.best = max(c.best, max(a.best,b.best));
    c.best = max(c.best, a.suf + b.pref);
    c.tot = a.tot+b.tot;
    return c;
}
void build(int nod,int st,int dr)
{
    if(st==dr)
    {
        int x;
        fin>>x;
        a[nod]= {x,x,x,x};
        return;
    }
    int mid = (st+dr)/2;
    build(nod*2,st,mid);
    build(nod*2+1,mid+1,dr);
    a[nod] = best(a[nod*2],a[nod*2+1]);
}
NODE query(int nod,int st,int dr,int x,int y)
{
    if(x<=st && dr<=y)
        return a[nod];
    int mid = (st+dr)/2;
    if(x<=mid && y>mid)
    {
        NODE a = query(nod*2,st,mid,x,y);
        NODE b = query(nod*2+1,mid+1,dr,x,y);
        return best(a,b);
    }
    if(x<=mid)
        return query(nod*2,st,mid,x,y);
    if(y>mid)
        return query(nod*2+1,mid+1,dr,x,y);
}

int main()
{
    int m;
    fin>>n>>m;
    build(1,1,n);
    for(int i=1; i<=m; i++)
    {
        int x,y;
        fin>>x>>y;
        fout<<query(1,1,n,x,y).best<<'\n';
    }

}