#include <fstream>
#include <algorithm>

using namespace std;

#define MAX_N 100000
#define LOG2_MAXN 16
const long long INF = 10000000001LL;

int N,a[MAX_N];
long long c[MAX_N+1],int_min[1<<(LOG2_MAXN+2)],int_max[1<<(LOG2_MAXN+2)];
long long int_best[1<<(LOG2_MAXN+2)];

void build_tree(int node, int lo, int hi){
	if(lo==hi){
		if(lo!=0){
			int_min[node] = c[lo-1];
			int_max[node] = c[lo];
			int_best[node] = c[lo]-c[lo-1];
		}else{
			int_min[node] = 0;
			int_max[node] = 0;
			int_best[node] = 0;
		}
	}else{
		int mi = (lo+hi)>>1;
		build_tree(2*node+1,lo,mi);
		build_tree(2*node+2,mi+1,hi);
		
		int_min[node] = min(int_min[2*node+1],int_min[2*node+2]);
		int_max[node] = max(int_max[2*node+1],int_max[2*node+2]);
		int_best[node] = max(int_max[2*node+2]-int_min[2*node+1],
						max(int_best[2*node+1],int_best[2*node+2]));
	}
}

void init(){
	c[0] = 0;
	for(int i = 0;i<N;++i) c[i+1] = c[i]+a[i];
	build_tree(0,0,N);
}

long long minPrefix;
int s,e;

long long tree_query(int node, int lo, int hi) {
	if (s<=lo && hi<=e) {
		long long  ret = int_best[node];
		if (minPrefix!=INF) ret = max(ret,int_max[node]-minPrefix);
		minPrefix = min(minPrefix,int_min[node]);
		return ret;
	}else{
		int mi = (lo+hi)>>1;
		
		if(mi<s) return tree_query(2*node+2,mi+1,hi);
		else if(mi>=e) return tree_query(2*node+1,lo,mi);
		else{
			long long val1 = tree_query(2*node+1,lo,mi);
			long long val2 = tree_query(2*node+2,mi+1,hi);
			return max(val1,val2);
		}
	}
}

int solve_msq(int x, int y){
	minPrefix = INF;
	s = x; e = y;
	return tree_query(0,0,N);
}

int main(){
	ifstream in("sequencequery.in");
	ofstream out("sequencequery.out");
	
	int Q,x,y;
	
	in>>N>>Q;
	for(int i = 0;i<N;++i) in>>a[i];
	
	init();
	
	for(int i = 0;i<Q;++i){
		in>>x>>y;
		out<<solve_msq(x,y)<<endl;
	}
	
	return 0;
}