#include <fstream>

using namespace std;
int v[100001];
ifstream cin("sequencequery.in");
ofstream cout("sequencequery.out");
long long searchmaxx(int x,int y)
{
    long long i,maxx=-999999999999LL,s=0;
    for(i=x;i<=y;i++)
    {
        s+=v[i];
        if(s>maxx) maxx=s;
        if(s<0)
            s=0;
    }
    return maxx;
}
int main()
{
    long long n,i,x,k,a,y;
    cin>>n>>k;
    for(i=1;i<=n;i++)
    {
        cin>>v[i];
    }
    for(a=1;a<=k;a++)
    {
        cin>>x>>y;
        cout<<searchmaxx(x,y)<<"\n";
    }
    return 0;
}