#include <bits/stdc++.h>
template <typename T>
void MACRO_VAR_Scan(T& t) {
  std::cin >> t;
}
template <typename First, typename... Rest>
void MACRO_VAR_Scan(First& first, Rest&... rest) {
  std::cin >> first;
  MACRO_VAR_Scan(rest...);
}
template <typename T>
void MACRO_VEC_ROW_Init(int n, T& t) {
  t.resize(n);
}
template <typename First, typename... Rest>
void MACRO_VEC_ROW_Init(int n, First& first, Rest&... rest) {
  first.resize(n);
  MACRO_VEC_ROW_Init(n, rest...);
}
template <typename T>
void MACRO_VEC_ROW_Scan(int p, T& t) {
  std::cin >> t[p];
}
template <typename First, typename... Rest>
void MACRO_VEC_ROW_Scan(int p, First& first, Rest&... rest) {
  std::cin >> first[p];
  MACRO_VEC_ROW_Scan(p, rest...);
}
template <class T>
inline T CHMAX(T& a, const T b) {
  return a = (a < b) ? b : a;
}
template <class T>
inline T CHMIN(T& a, const T b) {
  return a = (a > b) ? b : a;
}
template <class T>
std::vector<std::vector<T>> VV(int n, int m, T init = T()) {
  return std::vector<std::vector<T>>(n, std::vector<T>(m, init));
}
template <typename S, typename T>
std::ostream& operator<<(std::ostream& os, std::pair<S, T> p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using PAIR = std::pair<ll, ll>;
using PAIRLL = std::pair<ll, ll>;
constexpr ll INFINT = 1 << 30;
constexpr ll INFINT_LIM = (1LL << 31) - 1;
constexpr ll INFLL = 1LL << 60;
constexpr ll INFLL_LIM = (1LL << 62) - 1 + (1LL << 62);
constexpr double EPS = 1e-10;
constexpr ll MOD = 1000000007;
constexpr double PI = 3.141592653589793238462643383279;
template <class T, size_t N>
void FILL(T (&a)[N], const T& val) {
  for (auto& x : a) x = val;
}
template <class ARY, size_t N, size_t M, class T>
void FILL(ARY (&a)[N][M], const T& val) {
  for (auto& b : a) FILL(b, val);
}
template <class T>
void FILL(std::vector<T>& a, const T& val) {
  for (auto& x : a) x = val;
}
template <class ARY, class T>
void FILL(std::vector<std::vector<ARY>>& a, const T& val) {
  for (auto& b : a) FILL(b, val);
}
ll dp[100005];
enum QUERY_SEG_LazySegmentTree { SUM, MAX, MIN };
enum QUERY_LAZ_LazySegmentTree { ADD, UPD };
template <class SEG, class LAZ>
class LazySegmentTree {
 private:
  std::vector<SEG> seg;
  std::vector<LAZ> laz;
  std::vector<bool> isUpdated;
  ll ARY_SIZE;
  SEG eSeg;
  LAZ eLaz;
  std::function<SEG(SEG&, SEG&)> mergeSeg;
  std::function<LAZ(LAZ&, LAZ&)> mergeLaz;
  std::function<SEG(SEG&, LAZ&, ll)> applyLaz;
  void push(ll k, ll l, ll r) {
    if (!isUpdated[k]) {
      applyLaz(seg[k], laz[k], r - l);
      if (r - l > 1) {
        mergeLaz(laz[k * 2 + 1], laz[k]);
        isUpdated[k * 2 + 1] = false;
        mergeLaz(laz[k * 2 + 2], laz[k]);
        isUpdated[k * 2 + 2] = false;
      }
      isUpdated[k] = true;
      laz[k] = eLaz;
    }
  }

 public:
  LazySegmentTree(ll n, QUERY_SEG_LazySegmentTree qSeg,
                  QUERY_LAZ_LazySegmentTree qLaz)
      : ARY_SIZE(1) {
    ARY_SIZE = 1;
    while (ARY_SIZE < n) ARY_SIZE *= 2;
    seg.resize(ARY_SIZE * 2 - 1);
    laz.resize(ARY_SIZE * 2 - 1);
    isUpdated.resize(ARY_SIZE * 2 - 1, true);
    switch (qSeg) {
      case SUM:
        eSeg = 0;
        mergeSeg = [](SEG& l, SEG& r) { return l + r; };
        break;
      case MAX:
        eSeg = std::numeric_limits<SEG>::lowest();
        mergeSeg = [](SEG& l, SEG& r) { return std::max(l, r); };
        break;
      case MIN:
        eSeg = std::numeric_limits<SEG>::max();
        mergeSeg = [](SEG& l, SEG& r) { return std::min(l, r); };
        break;
      default:
        struct INVALID_QUERY_TYPE_ERROR {};
        throw INVALID_QUERY_TYPE_ERROR();
        break;
    }
    switch (qLaz) {
      case ADD:
        eLaz = 0;
        mergeLaz = [](LAZ& l, LAZ& r) { return l += r; };
        if (qSeg == SUM)
          applyLaz = [](SEG& s, LAZ& l, ll w) { return s += l * w; };
        else
          applyLaz = [](SEG& s, LAZ& l, ll w) { return s += l; };
        break;
      case UPD:
        eLaz = 0;
        mergeLaz = [](LAZ& l, LAZ& r) { return l = r; };
        if (qSeg == SUM)
          applyLaz = [](SEG& s, LAZ& l, ll w) { return s = l * w; };
        else
          applyLaz = [](SEG& s, LAZ& l, ll w) { return s = l; };
        break;
      default:
        struct INVALID_QUERY_TYPE_ERROR {};
        throw INVALID_QUERY_TYPE_ERROR();
        break;
    }
  }
  void update(ll a, ll b, SEG v, ll k, ll l, ll r) {
    push(k, l, r);
    if (r <= a || b <= l) return;
    if (a <= l && r <= b) {
      LAZ la(v);
      mergeLaz(laz[k], la);
      isUpdated[k] = false;
      push(k, l, r);
    } else {
      update(a, b, v, k * 2 + 1, l, (l + r) / 2);
      update(a, b, v, k * 2 + 2, (l + r) / 2, r);
      seg[k] = mergeSeg(seg[k * 2 + 1], seg[k * 2 + 2]);
    }
  }
  void update(ll l, ll r, SEG v) { update(l, r, v, 0, 0, ARY_SIZE); }
  SEG query(ll a, ll b, ll k, ll l, ll r) {
    push(k, l, r);
    if (r <= a || b <= l) return eSeg;
    if (a <= l && r <= b) return seg[k];
    SEG vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    SEG vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
    return mergeSeg(vl, vr);
  }
  SEG query(ll l, ll r) { return query(l, r, 0, 0, ARY_SIZE); }
};
using LST = LazySegmentTree<ll, ll>;
ll solve(std::vector<ll> x, ll T) {
  ll n = x.size();
  auto cost = [&](ll l, ll r) {
    if (r >= n | l >= r) return 0LL;
    if (T >= (x[r] - x[l]) * 2)
      return T;
    else
      return (x[r] - x[l]) * 2;
  };
  LST lst(n, MIN, ADD);
  dp[0] = T;
  for (ll i = (1); i < (n); ++i) {
    ll pre =
        std::lower_bound((x).begin(), (x).end(), x[i - 1] - T / 2) - x.begin();
    ll t = std::lower_bound((x).begin(), (x).end(), x[i] - T / 2) - x.begin();
    for (ll j = (pre); j < (t); ++j) {
      lst.update(j, j + 1, dp[j] + cost(j + 1, i) - lst.query(j, j + 1));
    }
    lst.update(0, pre, (x[i] - x[i - 1]) * 2);
    lst.update(i - 1, i, dp[i - 1] + T - lst.query(i - 1, i));
    dp[i] = std::min(lst.query(0, i), cost(0, i));
  }
  return dp[n - 1];
}
signed main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(0);
  ;
  ll n, e, t;
  MACRO_VAR_Scan(n, e, t);
  ;
  std::vector<ll> x(n);
  for (auto& i : x) std::cin >> i;
  ;
  ll ans = e;
  for (ll i = ll(n) - 1; i >= 0; --i) x[i] -= x[0];
  ans += solve(x, t);
  std::cout << (ans);
  std::cout << "\n";
  ;
  return 0;
}
