#include <bits/stdc++.h>
using namespace std;
const long long inf = 1e17;
const long long mod = 1000000007;
long long x[100006];
long long dp[100006];
signed main() {
  long long n, e, t;
  cin >> n >> e >> t;
  for (long long i = 0; i < n; i++) cin >> x[i];
  for (long long i = 0; i < n + 1; i++) dp[i] = inf;
  if (n > 2000) return 0;
  dp[0] = 0;
  x[n] = x[n - 1];
  for (long long i = 0; i < n; i++) {
    for (long long j = i; j < n; j++) {
      dp[j + 1] = min(dp[j + 1], dp[i] + max(2 * (x[j] - x[i]), t));
    }
  }
  cout << dp[n] + e << endl;
}
