#include <bits/stdc++.h>
#define fi first
#define se second
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
#define FORLL(i, a, b) for (ll i = a, _b = b; i <= _b; ++i)
#define FORDLL(i, a, b) for (ll i = a, _b = b; i >= _b; --i)
#define all(x) x.begin(), x.end()
#define uni(x) sort(all(x)), x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define dbg(...) debug(#__VA_ARGS__, __VA_ARGS__)
template<typename T>
void __prine_one(const char *&s, const T &x)
{
while (*s == ' ') ++s;
const char *p = s;
int bal = 0;
while (*s)
{
if (*s == '(') ++bal;
else if (*s == ')') --bal;
else if (*s == ',' && bal == 0) break;
++s;
}
cerr.write(p, s - p) << " = " << x;
if (*s == ',')
{
cerr << " , ";
++s;
}
}
template<typename... Args>
void debug(const char *s, Args... args)
{
cerr << "[ ";
int dummy[] = {0, (__prine_one(s, args), 0)...};
(void)dummy;
cerr << " ]\n\n";
}
template<class X, class Y>
bool maximize(const X &a, const X &b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
template<class X, class Y>
bool minimize(const X &a, const X &b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
// --------------------------------------------------------------------------------------------
const int maxn = 5e5 + 3;
int n, q;
ll a[maxn];
// --------------------------------------------------------------------------------------------
namespace sub2
{
bool approve()
{
return n <= 5000;
}
ll f[maxn][20], pre[5005][5005];
int lg[maxn];
ll get_max(int l, int r)
{
if (l > r) return 1e9;
int k = lg[r - l + 1];
return max(f[l][k], f[r - (1 << k) + 1][k]);
}
void solve()
{
FOR(i, 1, n)
f[i][0] = a[i];
FOR(j, 1, 19)
FOR(i, 1, n - (1 << j) + 1)
f[i][j] = max(f[i][j - 1], f[i + (1 << j - 1)][j - 1]);
FOR(i, 2, n)
lg[i] = lg[i >> 1] + 1;
FOR(i, 1, n - 2)
FOR(j, i + 2, n)
pre[i][j] = a[i] + a[j] + get_max(i + 1, i + (j - i) / 2);
FORD(l, n, 1)
FOR(r, 1, n)
{
pre[l][r] = max(pre[l][r], pre[l + 1][r]);
pre[l][r] = max(pre[l][r], pre[l][r - 1]);
}
while (q--)
{
int l, r; cin >> l >> r;
if (l > r)
return void(cout << 0 << '\n');
cout << pre[l][r] << '\n';
}
}
}
namespace sub3
{
ll suff[maxn];
bool approve()
{
return 1ll * n * q <= 3e7;
}
void solve()
{
while (q--)
{
vector<int> st;
int L, R; cin >> L >> R;
if (L > R)
return void(cout << "0\n");
suff[R] = a[R];
FORD(i, R - 1, L)
suff[i] = max(a[i], suff[i + 1]);
vector<pii> cand;
FOR(i, L, R)
{
while (st.size() && a[st.back()] <= a[i])
{
cand.push_back({st.back(), i});
st.pop_back();
}
if (st.size()) cand.push_back({st.back(), i});
st.push_back(i);
}
ll res = 0;
for (const auto &p : cand)
{
int x = p.fi, y = p.se;
if (y + y - x <= R)
res = max(res, a[x] + a[y] + suff[y + y - x]);
}
cout << res << '\n';
FOR(i, L, R)
suff[i] = 0;
}
}
}
namespace sub4
{
struct Node
{
ll sum2, sum3, lz;
Node()
{
sum2 = sum3 = -1e18;
lz = 0;
}
};
Node seg[maxn << 3];
vector<pii> AddCand[maxn];
vector<pii> qrs[maxn];
ll ans[maxn];
Node combine(const Node &left, const Node &right)
{
Node res;
res.sum2 = max(left.sum2, right.sum2);
res.sum3 = max(left.sum3, right.sum3);
return res;
}
void apply(int id, ll val)
{
seg[id].sum3 = max(seg[id].sum3, seg[id].sum2 + val);
seg[id].lz = max(seg[id].lz, val);
}
void push(int id)
{
if (seg[id].lz)
{
apply(id << 1, seg[id].lz); apply(id << 1 | 1, seg[id].lz);
seg[id].lz = 0;
}
}
void upd_se(int id, int l, int r, int pos, ll val)
{
if (l == r)
{
seg[id].sum2 = val;
seg[id].lz = 0;
return;
}
push(id);
int mid = l + r >> 1;
if (pos <= mid) upd_se(id << 1, l, mid, pos, val);
else upd_se(id << 1 | 1, mid + 1, r, pos, val);
seg[id] = combine(seg[id << 1], seg[id << 1 | 1]);
}
ll get(int id, int l, int r, int u, int v)
{
if (l > v || r < u) return 0ll;
if (l >= u && r <= v) return seg[id].sum3;
push(id);
int mid = l + r >> 1;
return max(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
}
void solve()
{
vector<int> st;
vector<pii> cand;
FOR(i, 1, n)
{
while (st.size() && a[st.back()] <= a[i])
{
if (i + i - st.back() <= n) cand.push_back({st.back(), i});
st.pop_back();
}
if (st.size() && i + i - st.back() <= n) cand.push_back({st.back(), i});
st.push_back(i);
}
sort(all(cand));
FOR(i, 0, (int)cand.size() - 1)
AddCand[cand[i].se + cand[i].se - cand[i].fi].push_back({i, a[cand[i].fi] + a[cand[i].se]});
FOR(iq, 1, q)
{
int l, r; cin >> l >> r;
if (l > r) continue;
qrs[r].push_back({l, iq});
}
FOR(r, 1, n)
{
for (const pii &p : AddCand[r])
{
// dbg(r,p.fi, p.se);
upd_se(1, 0, (int)cand.size() - 1, p.fi, p.se);
}
apply(1, a[r]);
// dbg(r, get(1, 0, (int)cand.size() - 1, 1, 1));
for (const pii &qr : qrs[r])
{
int l = qr.fi, id = qr.se;
int pos = lower_bound(all(cand), pii(l, -1e9)) - cand.begin();
// dbg(id, pos);
// ans[id] = get(1, 0, (int)cand.size() - 1, pos, pos);
ans[id] = get(1, 0, (int)cand.size() - 1, pos, (int)cand.size() - 1);
}
}
FOR(iq, 1, q)
cout << ans[iq] << '\n';
}
}
void solve()
{
cin >> n;
FOR(i, 1, n)
cin >> a[i];
cin >> q;
if (sub2 :: approve()) return sub2 :: solve(), void();
if (sub3 :: approve()) return sub3 :: solve(), void();
return sub4 :: solve(), void();
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define TASK "TEST"
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
freopen(TASK".OUT", "w", stdout);
}
solve();
return 0;
}
