#include <bits/stdc++.h>
using namespace std;
int n, x[100005], T, E;
long long f[100005], ans;
int main() {
  scanf("%d%d%d", &n, &E, &T);
  for (int i = 1; i <= n; i++) scanf("%d", x + i);
  for (int i = 1; i <= n; i++) f[i] = 1e16;
  for (int i = 1; i <= n; i++)
    for (int j = 1; j <= i; j++)
      f[i] = min(f[i], f[j - 1] + max(T, (x[i] - x[j]) * 2));
  ans = E + f[n];
  printf("%lld\n", ans);
  return 0;
}
