# include <bits/stdc++.h>
# define maxn 100001
# define ll long long
# define clock (clock() * 1000.0 / CLOCKS_PER_SEC)
# define rc(s) return cout << s,0
# define _ ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
# define pb push_back
# define mp make_pair
# define int ll
using namespace std;
const int inf = INT_MAX;

int a[maxn];
int n,m,l,r;

struct data
{
	int sum;
    int best;
    int lbest;
    int rbest;
}t[4 * maxn];

data combo(data a,data b)
{
    data tmp;
    tmp.sum = a.sum + b.sum;
    tmp.lbest = max({tmp.sum,a.lbest,a.sum + b.lbest});
    tmp.rbest = max({tmp.sum,b.rbest,b.sum + a.rbest});
    tmp.best = max({tmp.lbest,tmp.rbest,a.rbest+b.lbest,tmp.sum,a.best,b.best});
    return tmp;
};

void build(int nod,int l,int r)
{
	if(l == r)
	{
		t[nod] = {a[l],a[l],a[l],a[l]};
		return ;
	}
    int mid = l + r >> 1;
    build(nod << 1,l,mid);
    build(nod << 1 | 1,mid + 1,r);
    t[nod] = combo(t[nod << 1],t[nod << 1 | 1]);
}

data qry(int nod,int tl,int tr,int l,int r)
{
	if(l > r) return {-inf,-inf,-inf,-inf};
    if(l == tl && r == tr) return t[nod];
    int mid = tl + tr >> 1;
    return combo(qry(nod << 1,tl,mid,l,min(mid,r)),qry(nod << 1 | 1,mid + 1,tr,max(mid + 1,l),r));
}

int32_t main(){_
    freopen("sequencequery.in","r",stdin);
    freopen("sequencequery.out","w",stdout);
    cin >> n >> m;
    for(int i = 1;i<=n;i++)
		cin >> a[i];
	build(1,1,n);
	while(m --)
	{
		cin >> l >> r;
		cout << qry(1,1,n,l,r).best << '\n';
	}
	return 0;
}