#include <bits/stdc++.h>
using namespace std;
const long long MAX = 510000;
const long long MOD = 1000000007;
signed main() {
  long long n, e, t;
  cin >> n >> e >> t;
  long long x[n + 1], ans[n + 1];
  for (long long i = 1; i <= n; i++) cin >> x[i];
  ans[0] = e;
  for (long long i = 1; i <= n; i++) {
    ans[i] = ans[i - 1] + t;
    for (long long j = 1; j < i; j++) {
      ans[i] = min(ans[i], ans[j - 1] + max(t, 2 * (x[i] - x[j])));
    }
  }
  cout << ans[n] << endl;
}
