#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n, e, t;
  cin >> n >> e >> t;
  long long a[n];
  for (int i = 0; i < n; i++) cin >> a[i];
  long long dp[n + 1];
  dp[n] = 0;
  for (int i = n - 1; i >= 0; i--) {
    dp[i] = dp[i + 1] + t;
    for (int j = i + 1; j < n; j++) {
      dp[i] = min(dp[i], dp[j + 1] + max(2 * (a[j] - a[i]), t));
    }
  }
  cout << dp[0] + e << endl;
}
