#include <bits/stdc++.h>
#pragma GCC optimize(2)

using namespace std;

typedef long long ll;
const int MAXT = 300010;
const int MAXK = 15;
const int MAXX = 351943;

int T, op, k, c, x;
deque<int> q;

int main(int, char const *[])
{
  ios::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  cin >> T;
  while (T--)
  {
    cin >> op;
    if (op == 1)
    {
      cin >> x;
      q.push_front(x);
    }
    else if (op == 2)
    {
      cin >> x;
      q.push_back(x);
    }
    else if (op == 3)
      q.pop_front();
    else if (op == 4)
      q.pop_back();
    else if (op == 5)
    {
      cin >> k >> c;
      ll ans = 0;
      for (int i = 0; i < c; i++)
        ans += q[i * k];
      cout << ans << endl;
    }
    else
    {
      cin >> k >> c;
      ll ans = 0;
      for (int i = 0; i < c; i++)
        ans += q[q.size() - 1 - i * k];
      cout << ans << endl;
    }
  }
  return 0;
}