#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll inf = 3e18;
#define sz(x) (int)(x).size()
#define all(x) begin(x), end(x)
void solve() {
int n;
cin >> n;
vector<ll> a(n);
for (int i = 0; i < n; i++) {
cin >> a[i];
}
auto postmax = a;
for (int i = n-2; i >= 0; i--) {
postmax[i] = max(a[i], postmax[i+1]);
}
int q, l, r;
cin >> q >> l >> r;
assert(q == 1 && l == 1 && r == n);
auto Get = [&](int i) { return i >= 0 && i < n ? a[i] : 0; };
ll res = 0;
for (int i = 0; i < n; i++) {
ll mx = Get(i-1);
for (int j = i + 1; j < n; j++) {
res = max(res, a[i] + mx + postmax[j]);
mx = max({mx, Get(2*i-j), (j+i)%2 ? 0 : Get((j+i)/2)});
if (mx >= a[i]) break;
}
}
cout << res << "\n";
}
signed main() {
cin.tie(0)->sync_with_stdio(0);
solve();
return 0;
}
