# include <bits/stdc++.h>
# define maxn 100005
# 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);
# define pb push_back
# define int ll
using namespace std;

struct rudi
{
    int sum,pref,suff,ans;
}t[4 * maxn];

int n,q,x,y,a[maxn];

rudi make(int val)
{
    rudi ans;
    ans.pref = ans.suff = ans.ans = ans.sum = val;
    return ans;
}

rudi combo(rudi l,rudi r)
{
    rudi ans;
    ans.sum = l.sum + r.sum;
    ans.pref = max(l.pref,l.sum + r.pref);
    ans.suff = max(r.suff,r.sum + l.suff);
    ans.ans = max(max(l.ans,r.ans),l.suff+r.pref);
    return ans;
}

void build(int nod,int l, int r)
{
    if(l == r)
        t[nod] = make(a[l]);
    else
    {
        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]);
    }
}

rudi qry(int nod,int tl,int tr,int l,int r)
{
    if(l > r)
        return make(INT_MIN);
    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 >> q;
    for(int i = 1;i<=n;i++)
        cin >> a[i];
    build(1,1,n);
    for(int i = 1;i<=q;i++)
    {
        cin >> x >> y;
        cout << qry(1,1,n,x,y).ans << "\n"[i == q];
    }
    return 0;
}