#include <bits/stdc++.h>
using namespace std;
using namespace placeholders;
using LL = long long;
using ULL = unsigned long long;
using VI = vector<int>;
using VVI = vector<vector<int> >;
using VS = vector<string>;
using ISS = istringstream;
using OSS = ostringstream;
using PII = pair<int, int>;
using VPII = vector<pair<int, int> >;
template <typename T = int>
using VT = vector<T>;
template <typename T = int>
using VVT = vector<vector<T> >;
template <typename T = int>
using LIM = numeric_limits<T>;
template <typename T>
inline istream &operator>>(istream &s, vector<T> &v) {
  for (T &t : v) {
    s >> t;
  }
  return s;
}
template <typename T>
inline ostream &operator<<(ostream &s, const vector<T> &v) {
  for (int i = 0; i < int(v.size()); ++i) {
    s << (" " + !i) << v[i];
  }
  return s;
}
template <typename T>
inline T fromString(const string &s) {
  T res;
  istringstream iss(s);
  iss >> res;
  return res;
}
template <typename T>
inline string toString(const T &a) {
  ostringstream oss;
  oss << a;
  return oss.str();
}
template <typename T>
inline bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
inline bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
constexpr auto INF = LIM<LL>::max() / 2;
LL dp[1 << 17];
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  cout << setprecision(12) << fixed;
  int N, E, T;
  scanf("%d%d%d", &N, &E, &T);
  VI X(N);
  for_each(begin(X), end(X), [](int &x) { scanf("%d", &x); });
  if (2000 < N) {
    return 1;
  }
  fill(begin(dp), end(dp), INF);
  dp[0] = 0;
  for (int i = (int)(0); i < (int)(N); ++i) {
    for (int j = (int)(i); j < (int)(N); ++j) {
      chmin(dp[j + 1], dp[i] + max(T, 2 * (X[j] - X[i])));
    }
  }
  printf("%lld\n", E + dp[N]);
  fflush(stdout);
  return 0;
}
