#include <fstream>

using namespace std;
ifstream f("sequencequery.in");
ofstream g("sequencequery.out");
int n,m,i,j,s,min1,max1,a[100005],x,y;
int main()
{
    f>>n>>m;
    for(i=1;i<=n;i++)
        f>>a[i];

    for(j=1;j<=m;j++)
    {
    f>>x>>y;
    s=0;
    min1=9999999;
    max1=-999999999;
    for(i=x;i<=y;i++)
    {
        s=s+a[i];
        if(s-min1>max1){max1=s-min1;}
        if(s<min1){min1=s;}

    }
    if(x==y)max1=a[x];
    g<<max1<<'\n';
    }
    return 0;
}