#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1e9 + 7;
const int INF = 1e9;
const long long IINF = 1e18;
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
const char dir[4] = {'D', 'R', 'U', 'L'};
template <typename T>
istream &operator>>(istream &is, vector<T> &v) {
  for (T &x : v) is >> x;
  return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v) {
  for (int i = 0; i < v.size(); ++i) {
    os << v[i] << (i + 1 == v.size() ? "" : " ");
  }
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
  cout << '(' << p.first << ',' << p.second << ')';
  return os;
}
template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &m) {
  os << '{';
  for (auto itr = m.begin(); itr != m.end(); ++itr) {
    os << '(' << itr->first << ',' << itr->second << ')';
    if (++itr != m.end()) os << ',';
    --itr;
  }
  os << '}';
  return os;
}
template <typename T>
ostream &operator<<(ostream &os, const set<T> &s) {
  os << '{';
  for (auto itr = s.begin(); itr != s.end(); ++itr) {
    os << *itr;
    if (++itr != s.end()) os << ',';
    --itr;
  }
  os << '}';
  return os;
}
void debug_out() { cerr << '\n'; }
template <class Head, class... Tail>
void debug_out(Head &&head, Tail &&...tail) {
  cerr << head;
  if (sizeof...(Tail) > 0) cerr << ", ";
  debug_out(move(tail)...);
}
template <typename T>
T gcd(T x, T y) {
  return y != 0 ? gcd(y, x % y) : x;
}
template <typename T>
T lcm(T x, T y) {
  return x / gcd(x, y) * y;
}
template <class T1, class T2>
inline bool chmin(T1 &a, T2 b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T1, class T2>
inline bool chmax(T1 &a, T2 b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename Monoid>
struct SegmentTree {
  typedef function<Monoid(Monoid, Monoid)> F;
  int n;
  F f;
  Monoid id;
  vector<Monoid> dat;
  SegmentTree(int n_, F f, Monoid id) : f(f), id(id) { init(n_); }
  void init(int n_) {
    n = 1;
    while (n < n_) n <<= 1;
    dat.assign(n << 1, id);
  }
  void build(const vector<Monoid> &v) {
    for (int i = 0; i < v.size(); ++i) dat[i + n] = v[i];
    for (int i = n - 1; i; --i) dat[i] = f(dat[i << 1 | 0], dat[i << 1 | 1]);
  }
  void update(int k, Monoid x) {
    dat[k += n] = x;
    while (k >>= 1) dat[k] = f(dat[k << 1 | 0], dat[k << 1 | 1]);
  }
  Monoid query(int a, int b) {
    if (a >= b) return id;
    Monoid vl = id, vr = id;
    for (int l = a + n, r = b + n; l < r; l >>= 1, r >>= 1) {
      if (l & 1) vl = f(vl, dat[l++]);
      if (r & 1) vr = f(dat[--r], vr);
    }
    return f(vl, vr);
  }
  Monoid operator[](int i) { return dat[i + n]; }
  template <typename C>
  int find(int a, int b, const C &check, int k, int l, int r) {
    if (!check(dat[k]) || r <= a || b <= l) return -1;
    if (l + 1 == r) return k - n;
    int vl = find(a, b, check, k << 1 | 0, l, (l + r) >> 1);
    if (~vl) return vl;
    return find(a, b, check, k << 1 | 1, (l + r) >> 1, r);
  }
  template <typename C>
  int find(int a, int b, const C &check) {
    return find(a, b, check, 1, 0, n);
  }
};
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int N;
  long long E, T;
  cin >> N >> E >> T;
  vector<long long> x(N + 1);
  x[0] = 0;
  for (int i = 1; i <= N; ++i) cin >> x[i];
  vector<long long> x_2(N + 1);
  for (int i = 0; i <= N; ++i) x_2[i] = x[i] * 2;
  vector<long long> dp(N + 1, IINF), dp0(N + 1);
  SegmentTree<long long> seg(
      N + 1, [](long long a, long long b) { return min(a, b); }, IINF);
  dp[0] = 0;
  dp0[0] = -2 * x[1];
  seg.update(0, 0);
  for (int i = 1; i <= N; ++i) {
    int pos = lower_bound(x_2.begin(), x_2.end(), x_2[i] - T) - x_2.begin() - 2;
    if (~pos) dp[i] = min(dp[i], dp0[pos] + 3 * x[i]);
    dp[i] = min(dp[i], seg.query(max(0, pos + 1), i) + T + x[i]);
    if (i == N) continue;
    dp0[i] = min(dp0[i - 1], dp[i] - x_2[i + 1] - x[i]);
    seg.update(i, dp[i] - x[i]);
  }
  cout << dp[N] + (E - x[N]) << '\n';
}
