#include <iostream>
#include <fstream>
using namespace std;
struct node{
    long long prefix;
    long long suffix;
    long long sum;
    long long ans;
};
long long a[100100];
node tree[2*(100100) +20];

void build(long long nodes,long long start,long long end){
    if(start == end){
        tree[nodes].prefix = a[start];
        tree[nodes].suffix = a[start];
        tree[nodes].sum = a[start];
        tree[nodes].ans = a[start];
        
    }else{
        long long mid = (start+end)/2;
        build(2*nodes,start,mid);
        build(2*nodes+1,mid+1,end);
        tree[nodes].prefix = max(tree[2*nodes].prefix,tree[2*nodes].sum+tree[2*nodes+1].prefix);
        tree[nodes].suffix = max(tree[2*nodes+1].suffix, tree[2*nodes+1].sum+tree[2*nodes].suffix);
        tree[nodes].sum = tree[2*nodes].sum+tree[2*nodes+1].sum;
        tree[nodes].ans = max(tree[2*nodes].ans,max(tree[2*nodes+1].ans,tree[2*nodes].suffix+tree[2*nodes+1].prefix));
       //  std::fout<<start<<" "<<end<<" "<<tree[nodes].ans<<endl;
    }
    
}

node query(long long nodes,long long start,long long end,long long l, long long r){
    if(r<start||end<l){
        node temp;
        temp.prefix =-10000000;
        temp.suffix =-10000000;
        temp.sum = -10000000;
        temp.ans = -10000000;
        return temp;
    }else{
        if(l<=start && end<=r){
            return tree[nodes];
        }
        long long mid = (start+end)/2;
        
        node p1 = query(2*nodes,start,mid,l,r);
        node p2 = query(2*nodes+1,mid+1,end,l,r);
        node temp;
        temp.prefix = max(p1.prefix,p1.sum+p2.prefix);
        temp.suffix = max(p2.suffix, p2.sum+p1.suffix);
        temp.sum = p1.sum+p2.sum;
        temp.ans = max(p1.ans,max(p2.ans,p1.suffix+p2.prefix));
        
        return temp;
    }
}
int main() {
    ifstream fin("sequencequery.in");
    ofstream fout("sequencequery.out");
	long long n,m;
	fin>>n>>m;
	for(long long i=1;i<=n;i++){
	    fin>>a[i];
	}
	build(1,1,n);
	for(long long i=0;i<m;i++){
	    long long l,r;
	    fin>>l>>r;
	    node hold = query(1,1,n,l,r);
	    std::fout<<hold.ans<<endl;
	}
}