#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define bigint __int128
#define emb emplace_back
#define pb push_back
#define pii pair <int, int>
#define fi first
#define se second
#define all(v) v.begin(), v.end()
#define Task ""
#define MASK(k) (1ull << k)
#define bitcnt(k) __builtin_popcount(k)
#define testBit(n, k) ((n >> k) & 1)
#define flipBit(n, k) (n ^ (1ll << k))
#define offBit(n, k) (n & ~MASK(k))
#define onBit(n, k) (n | (1ll << k))
template <class T> bool minimize(T &a, T b) {if (a > b) {a = b; return true;} return false;}
template <class T> bool maximize(T &a, T b) {if (a < b) {a = b; return true;} return false;}
const int N = 5e5 + 5, lim = 60, mod = 1e9 + 7;
const ll INF = 1e18;
int n, q, a[N];
int l[N], r[N];
namespace sub2 {
int f[5005][5005];
void solve() {
for (int x = 1; x <= n - 2; x++) {
for (int z = x + 2, y = x + 1, ma = a[y]; z <= n; z++) {
while ((y + 1) * 2 <= x + z) maximize(ma, a[++y]);
f[x][z] = a[x] + ma + a[z];
}
}
for (int len = 4; len <= n; len++)
for (int x = 1, z = len; z <= n; x++, z++)
maximize(f[x][z], max(f[x][z - 1], f[x + 1][z]));
for (int i = 1; i <= q; i++)
cout << f[l[i]][r[i]] << '\n';
}
}
namespace sub3 {
int sufMa[N];
vector <pii> candidate;
void solve() {
for (int i = n; i > 0; i--)
sufMa[i] = max(sufMa[i + 1], a[i]);
// nhung cap (a, b) : max(A[a+1, b-1]) < min(A[a], A[b])
stack <int> st;
for (int i = 1; i <= n; i++) {
while (!st.empty() && a[st.top()] <= a[i]) {
// neu truoc i ton tai k ma A[x] <= A[k] -> x da bi bo / neu ko thi A[x] lon nhat
// den khi A[x] <= A[i] -> x va i la 2 dau mut lon nhat
candidate.emplace_back(st.top(), i);
st.pop();
}
if (!st.empty()) {
// A[st.top()] > A[st.top() + 1 ... i]
// cap nay co the chac chan thoa khi A[st.top] > A[i] > max o giua
// nhung vi tri trong st con lai ko thoa vi co max_mid >= A[st.top()] > A[i]
candidate.emplace_back(st.top(), i);
}
st.emplace(i);
}
int ans = 0;
for (auto [x, y]: candidate) {
int miZ = 2 * y - x;
if (miZ <= n) maximize(ans, a[x] + a[y] + sufMa[miZ]);
}
cout << ans;
}
}
namespace sub4 {
struct Node {
int mxF, mxA, mxAns;
Node () {}
Node (int a, int b, int c) {
mxF = a; mxA = b; mxAns = c;
}
// l <= i <= j <= r -> mxAns = max(Fi + Aj)
Node operator + (const Node &other) {
Node res;
res.mxF = max(mxF, other.mxF);
res.mxA = max(mxA, other.mxA);
res.mxAns = max({mxAns, other.mxAns, mxF + other.mxA});
return res;
}
};
struct SegmentTree {
vector <Node> node;
SegmentTree (int len) {
node.assign(len * 4 + 1, Node());
}
void build(int id, int l, int r) {
if (l == r) {
node[id] = Node(0, a[l], a[l]);
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid); build(id << 1 | 1, mid + 1, r);
node[id] = node[id << 1] + node[id << 1 | 1];
}
void update(int id, int l, int r, int p, int f) {
if (l == r) {
maximize(f, node[id].mxF);
node[id] = Node(f, a[l], f + a[l]);
return;
}
int mid = (l + r) >> 1;
if (p <= mid) update(id << 1, l, mid, p, f);
else update(id << 1 | 1, mid + 1, r, p, f);
node[id] = node[id << 1] + node[id << 1 | 1];
}
Node get(int id, int l, int r, int u, int v) {
if (u > r || v < l) return Node(0, 0, 0);
if (u <= l && r <= v) return node[id];
int mid = (l + r) >> 1;
return get(id << 1, l, mid, u, v) + get(id << 1 | 1, mid + 1, r, u, v);
}
};
vector <int> candidate[N];
vector <pii> query[N];
void solve() {
stack <int> st;
for (int i = 1; i <= n; i++) {
while (!st.empty() && a[st.top()] <= a[i]) {
// neu truoc i ton tai k ma A[x] <= A[k] -> x da bi bo / neu ko thi A[x] lon nhat
// den khi A[x] <= A[i] -> x va i la 2 dau mut lon nhat
candidate[st.top()].emplace_back(i);
st.pop();
}
if (!st.empty()) {
// A[st.top()] > A[st.top() + 1 ... i]
// cap nay co the chac chan thoa khi A[st.top] > A[i] > max o giua
// nhung vi tri trong st con lai ko thoa vi co max_mid >= A[st.top()] > A[i]
candidate[st.top()].emplace_back(i);
}
st.emplace(i);
}
for (int i = 1; i <= q; i++) {
query[l[i]].emplace_back(r[i], i);
}
SegmentTree ST(n); vector <int> ans(q + 1);
ST.build(1, 1, n);
for (int l = n; l > 0; l--) {
for (int b: candidate[l]) if (2 * b - l <= n) {
ST.update(1, 1, n, 2 * b - l, a[l] + a[b]);
}
for (auto [r, id]: query[l]) {
ans[id] = ST.get(1, 1, n, l, r).mxAns;
}
}
for (int i = 1; i <= q; i++)
cout << ans[i] << '\n';
}
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
if (fopen(Task".inp", "r")) {
freopen(Task".inp", "r", stdin);
freopen(Task".out", "w", stdout);
}
cin >> n;
for (int i = 1; i <= n; i++) cin >> a[i];
cin >> q;
for (int i = 1; i <= q; i++) cin >> l[i] >> r[i];
if (n <= 5e3) sub2::solve();
else if (q == 1 && l[1] == 1 && r[1] == n) sub3::solve();
else sub4::solve();
}
