This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
#define int long long
struct node
{
    int s, e, m, v;
    node *l, *r;
    node(int _s, int _e) : s(_s), e(_e), m((_s + _e) / 2), v(0)
    {
        if (s != e)
            l = new node(s, m),
            r = new node(m + 1, e);
    }
    void upd(int n, int x)
    {
        if (s == e)
        {
            v = x;
            return;
        }
        if (n <= m)
            l->upd(n, x);
        else
            r->upd(n, x);
        v = max(l->v, r->v);
    }
    int qry(int a, int b)
    {
        if (b < s || a > e)
            return -1;
        if (a <= s && b >= e)
            return v;
        return max(l->qry(a, b), r->qry(a, b));
    }
} *root;
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int N, x, Q, l, r;
    cin >> N;
    vector<int> stiff;
    root = new node(0, N - 1);
    for (int i = 0; i < N; i++)
    {
        cin >> x;
        root->upd(i, x);
        stiff.push_back(x);
    }
    vector<vector<int>> precomp(N, vector<int>(N, -1)), prefix(N, vector<int>(N, -1)), ans(N, vector<int>(N, -1));
    for (int i = 0; i < N; i++)
    {
        for (int j = i + 2; j < N; j++)
        {
            precomp[i][j] = stiff[i] + stiff[j] + root->qry(i + 1, (i + j) / 2);
        }
    }
    for (int i = N - 1; i >= 0; i--)
    {
        for (int j = i + 2; j < N; j++)
        {
            prefix[i][j] = max(prefix[i + 1][j], precomp[i][j]);
        }
    }
    for (int i = 0; i < N; i++)
    {
        for (int j = i + 2; j < N; j++)
        {
            ans[i][j] = max(ans[i][j - 1], prefix[i][j]);
        }
    }
    cin >> Q;
    for (int i = 0; i < Q; i++)
    {
        cin >> l >> r;
        l--, r--;
        cout << ans[l][r] << '\n';
    }
}
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