#include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll Mod = 998244353;
constexpr ll mod = 1e9 + 7;
constexpr ll inf = 1LL << 60;
const double PI = acos(-1);
template <typename T1, typename T2>
inline bool chmax(T1 &a, T2 b) {
  return a < b && (a = b, true);
}
template <typename T1, typename T2>
inline bool chmin(T1 &a, T2 b) {
  return a > b && (a = b, true);
}
ll n, t, e;
ll x[100009];
ll dp[100009];
int main() {
  cin.tie(nullptr);
  ios::sync_with_stdio(false);
  cin >> n >> e >> t;
  assert(n <= 2000);
  for (ll i = (ll)0; i < (ll)n; i++) cin >> x[i + 1];
  fill(begin(dp), end(dp), inf);
  dp[0] = 0;
  for (ll i = (ll)1; i < (ll)n + 1; i++)
    for (ll j = (ll)0; j < (ll)i; j++)
      chmin(dp[i], dp[j] + max(t, 2 * (x[i] - x[j + 1])));
  cout << dp[n] + e << endl;
  return 0;
}
