#include<iostream>
#include<fstream>

#define nm 100005

using namespace std;

int v[nm],n,m;

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

struct interval
{
	int x,y;
	int s;
}a[nm];

int detSecv(int c,int b)
{
	int max=-1<<30;
	if(c!=b&&c<b)
	{
		for(int i=c;i<b;++i)
		{
			int s=0;
			for(int j=i+1;j<=b;++j)
			{
				s+=v[j];
				if(s>max)
					max=s;
			}
		}
		return max;
	}
	else if(c==b)
		return v[c];
}

int main()
{
	f>>n>>m;
	for(int i=1;i<=n;++i)
		f>>v[i];
	for(int i=1;i<=m;++i)
	{
		f>>a[i].x>>a[i].y;
		a[i].s=detSecv(a[i].x,a[i].y);
	}
	for(int i=1;i<=m;++i)
		g<<a[i].s<<'\n';
}