#include <bits/stdc++.h>
#include <fstream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
template<class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
struct custom_hash {static uint64_t splitmix64(uint64_t x) {x += 0x9e3779b97f4a7c15;x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;x = (x ^ (x >> 27)) * 0x94d049bb133111eb;return x ^ (x >> 31);}size_t operator()(uint64_t x) const {static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();return splitmix64(x + FIXED_RANDOM);}};
string __fname = "sequencequery"; ifstream in (__fname + ".in"); ofstream out (__fname + ".out"); 
#define cin in 
#define cout out
#define int64 long long
#define uint64 unsigned long long
#define x first
#define y second
#define pb push_back
#define pii pair <int, int> 
#define pii64 pair <int64, int64>
#define db(x) cout << "> " << #x << ": " << (x) << "\n"
#define qr queries()
#define yn(x) if (x) {ctn("Yes");}else {ctn("No");}
void solve(int);
void queries(){int n;cin >> n;for (int i = 1; i <= n; i++) solve(i);}
template<class T>T ceildiv(T a, T b) {return a / b + !!(a % b);}
template<class T>T gcd (T a, T b){return (b ? gcd(b, a % b): a);}
template<class T>T lcm (T a, T b){return a * b / gcd(a, b);}
// // // // // // // // // // // // // // // // // // // // // // 
/*                  TEMPLATE - VANILLA                         */
// // // // // // // // // // // // // // // // // // // // // //
const int ddx[] = {-1, -1, 0, 1, 1, 1, 0, -1};
const int ddy[] = {0, 1, 1, 1, 0, -1, -1, -1};
const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, 1, 0, -1};
const double pi = 3.14159265359;
const double eps = 1e-6;
const int64 hash_inv = 940594066;
const int64 hash_p = 101;
const int64 mod = 1000000007;
const int maxn = 100002;
int a[maxn];

struct node {
    int64 sum;
    int64 l;
    int64 r;
    int64 ans;

    node() {
        sum = 0;
        l = r = ans = -1e9;
    }
    node(int v) {
        sum = l = r = ans = v;
    }
};

node sgt [maxn * 4];

node merge (node a, node b){
    node nw;
    nw.sum = a.sum + b.sum;
    nw.l = max(a.l, a.sum + b.l);
    nw.r = max(b.r, b.sum + a.r);
    nw.ans = max({a.r + b.l, a.ans, b.ans});
    return nw;
}

node build (int nd, int l, int r) {
    if (l == r) return sgt[nd] = node(a[l]);
    int mid = (l + r) / 2;
    return sgt[nd] = merge(build(nd * 2, l, mid), build(nd * 2 + 1, mid + 1, r));
}

node query (int nd, int l, int r, int _l, int _r) {
    if (l >= _l && r <= _r) return sgt[nd];
    if (l > _r || r < _l) return node();
    int mid = (l + r) / 2;
    return merge(query(nd * 2, l, mid, _l, _r), query(nd * 2 + 1, mid + 1, r, _l, _r));
}

node update (int nd, int l, int r, int tg) {
    if (l == r) return sgt[l] = node(a[l]);
    if (l > tg || r < tg) return node();
    int mid = (l + r) / 2;
    return sgt[nd] = merge(update(nd * 2, l, mid, tg), update(nd * 2 + 1, mid + 1, r, tg));
}

void solve(int id){
    
    return;
}


int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout << fixed; cout << setprecision(10); 
    int n,k;
    cin >> n >> k;
    for (int i = 1; i <= n; i++){
        cin >> a[i];
    }
    build(1, 1, n);
    for (int i = 0; i < k; i++){
        int l,r;
        cin >> l >> r;
        cout << query(1, 1, n, l, r).ans << "\n";
    }
    return 0;
}