#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 7, INF = 1e18 + 7;
long long n, T, E, a[N], dp[N];
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cin >> n >> E >> T;
  for (long long i = 1; i <= n; ++i) cin >> a[i];
  for (long long i = 1; i <= n; ++i) {
    dp[i] = INF;
    for (long long j = 1; j <= i; ++j) {
      dp[i] = min(dp[i], dp[j - 1] + max(T, 2 * (a[i] - a[j])));
    }
  }
  cout << dp[n] + E << '\n';
}
