#include <bits/stdc++.h>
using namespace std;
long long n, e, t, a[100010], dt[100010];
long long dp(int x) {
  if (x == n) return e - a[n];
  if (dt[x]) return dt[x];
  long long &ret = dt[x] = 9876543210000000LL;
  for (int i = x + 1; i <= n; i++)
    ret = min(ret, dp(i) + a[i] - a[x] +
                       min(max(t, 2 * (a[i] - a[x + 1])), t * (i - x)));
  return ret;
}
int main() {
  ios::sync_with_stdio(false);
  cin >> n >> e >> t;
  for (int i = 1; i <= n; i++) cin >> a[i];
  a[0] = 0, a[n + 1] = e;
  cout << dp(0) << endl;
}
