#include <fstream>
#include <climits>

using namespace std;

ifstream f("sequencequery.in");
ofstream g("sequencequery.out");

int main()
{
    int n,m,x,y,a[10000],j,s,smax,i;
    f>>n>>m;
    smax=LONG_MAX;
    for (i=1;i<=n;i++)
    {
        f>>a[i];
    }
    for (i=1;i<=m;i++)
    {
        f>>x>>y;
        s=0;
        smax=0;
        for (j=x;j<=y;j++)
        {
            s+=a[j];
              if (s>smax)
            {
              smax=s;
            }
            else
            {
                if (s<0&&smax==0)
                {
                    smax=s;
                }
            }
            if (s<0)
            {
                s=0;
            }
        }
        g<<smax<<" ";
    }
    return 0;
}