#include <bits/stdc++.h>
using namespace std;
const int N = 123;
const int M = 123;
const double Pi = acos(-1);
const long long Inf = 1e18;
const int inf = 1e9;
const int mod = 1e9 + 7;
const int Sz = 501;
const int MOD = 1e9 + 7;
void add(int &a, int b) {
  a += b;
  if (a >= mod) a -= mod;
}
int mult(int a, int b) { return 1ll * a * b % mod; }
int sum(int a, int b) {
  add(a, b);
  return a;
}
int n, a[N], t, m;
long long dp[N];
long long calc(int l, int r) {
  long long ans = max((a[r] - a[l]) * 2ll, 1ll * t);
  return ans;
}
void solve() {
  cin >> n >> m >> t;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    dp[i] = 1e18;
  }
  for (int i = 1; i <= n; i++) {
    for (int j = 1; j <= i; j++) {
      long long cur = dp[j - 1] + calc(j, i);
      dp[i] = min(dp[i], cur);
    }
  }
  cout << dp[n] + m << endl;
}
int main() {
  ios_base::sync_with_stdio(0);
  int tt = 1;
  while (tt--) solve();
  return 0;
}
