#include <fstream>
#include <vector>
#include <queue>
#define INF 2e9
using namespace std;
ifstream fin ("sequencequery.in");
ofstream fout("sequencequery.out");
int i,j,Q,n,t,x,y,val,m,V[100005],sol;
struct elem
{
long long suma,st,dr,ssm;
}A[400003];
elem U(elem x,elem y)
{
elem z;
z.suma=x.suma+y.suma;
z.st=max(x.st,x.suma+y.st);
z.dr=max(y.dr,y.suma+x.dr);
z.ssm=max(y.st+x.dr,max(x.ssm,y.ssm));
return z;
}
void build(int nod,int st,int dr)
{
if(st==dr)
A[nod]={V[st],V[st],V[st],V[st]};
else
{
int mid=(st+dr)/2;
build(2*nod,st,mid);
build(2*nod+1,mid+1,dr);
A[nod]=U(A[2*nod],A[2*nod+1]);
}
}
elem query(int nod,int st,int dr,int a,int b)
{
if(a<=st&&dr<=b)
return A[nod];
else
{
int mid=(st+dr)/2;
if(a<=mid&&mid+1<=b)
return U(query(2*nod,st,mid,a,b),query(2*nod+1,mid+1,dr,a,b));
if(a<=mid)
return query(2*nod,st,mid,a,b);
if(mid+1<=b)
return query(2*nod+1,mid+1,dr,a,b);
}
}
int main()
{
fin>>n>>Q;
for(i=1;i<=n;i++)
fin>>V[i];
build(1,1,n);
while(Q--)
{
fin>>x>>y;
fout<<query(1,1,n,x,y).ssm<<"\n";
}
return 0;
}