# 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 = max(0LL,val);
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;
}