#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 7;
const int inf = INT_MAX;
const long long inff = 1e18;
const long long mod = 1e9 + 7;
vector<int> dx = {0, 1, 1, 1, 0, -1, -1, -1};
vector<int> dy = {1, 1, 0, -1, -1, -1, 0, 1};
int can[507][507];
set<pair<int, int> > second[32][9];
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  int a[35];
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int j = 250; j <= 250 + a[1] - 1; j++) can[250][j] = 1;
  second[1][0].insert(make_pair(250, 250 + a[1] - 1));
  for (int i = 1; i < n; i++) {
    for (int j = 0; j < 8; j++) {
      for (pair<int, int> k : second[i][j]) {
        for (int l = 1; l <= a[i + 1]; l++) {
          can[k.first + dx[(j + 1) % 8] * l][k.second + dy[(j + 1) % 8] * l] =
              1;
          can[k.first + dx[(j + 7) % 8] * l][k.second + dy[(j + 7) % 8] * l] =
              1;
        }
        second[i + 1][(j + 1) % 8].insert(
            make_pair(k.first + dx[(j + 1) % 8] * a[i + 1],
                      k.second + dy[(j + 1) % 8] * a[i + 1]));
        second[i + 1][(j + 7) % 8].insert(
            make_pair(k.first + dx[(j + 7) % 8] * a[i + 1],
                      k.second + dy[(j + 7) % 8] * a[i + 1]));
      }
    }
  }
  int ans = 0;
  for (int i = 0; i <= 500; i++)
    for (int j = 0; j <= 500; j++) ans += can[i][j];
  cout << ans << '\n';
}
