#include <bits/stdc++.h>
using namespace std;

ifstream fin("sequencequery.in");
ofstream fout("sequencequery.out");

int v[100005];

int kadane(int n, int m)
{
    int sumamaxima,sumacurenta;
    sumamaxima = v[n], sumacurenta = v[n];
    for (int i=n+1;i<=m;i++)
    {
        if (sumacurenta<0)
        {
            sumacurenta = v[i];
        }
        else sumacurenta = sumacurenta + v[i];
        if (sumacurenta > sumamaxima)
        {
            sumamaxima = sumacurenta;
        }
    }
    return sumamaxima;
}

int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=1;i<=n;i++) fin>>v[i];
    int x,y;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        fout<<kadane(x,y)<<'\n';
    }
}