#include <bits/stdc++.h>
char buf[(1 << 22)], *p1 = buf, *p2 = buf;
using namespace std;
const int MAXN = 2001, mod = 998244353, INF = 1e9 + 10;
const double eps = 1e-9;
template <typename A, typename B>
inline bool chmin(A &a, B b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename A, typename B>
inline bool chmax(A &a, B b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <typename A, typename B>
inline long long add(A x, B y) {
  if (x + y < 0) return x + y + mod;
  return x + y >= mod ? x + y - mod : x + y;
}
template <typename A, typename B>
inline void add2(A &x, B y) {
  if (x + y < 0)
    x = x + y + mod;
  else
    x = (x + y >= mod ? x + y - mod : x + y);
}
template <typename A, typename B>
inline long long mul(A x, B y) {
  return 1ll * x * y % mod;
}
template <typename A, typename B>
inline void mul2(A &x, B y) {
  x = (1ll * x * y % mod + mod) % mod;
}
template <typename A>
inline void debug(A a) {
  cout << a << '\n';
}
template <typename A>
inline long long sqr(A x) {
  return 1ll * x * x;
}
inline int read() {
  char c = getchar();
  int x = 0, f = 1;
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar();
  return x * f;
}
long long N, E, T, a[MAXN], f[MAXN];
int main() {
  N = read();
  E = read();
  T = read();
  memset(f, 0x3f, sizeof(f));
  for (int i = 1; i <= N; i++) a[i] = read();
  f[0] = 0;
  f[1] = T;
  for (int i = 2; i <= N; i++) {
    for (int j = i - 1; j >= 0; j--)
      chmin(f[i], f[j] + max(T, 2 * (a[i] - a[j + 1])));
  }
  cout << f[N] + E;
  return 0;
}
