#include <bits/stdc++.h>
#define SZ(x) ((int) (x).size())
using namespace std;

typedef long long i64;

int main() {
    #ifdef LOCAL_RUN
    freopen("task.in", "r", stdin);
    freopen("task.out", "w", stdout);
    //freopen("task.err", "w", stderr);
    #endif // ONLINE_JUDGE
    ios::sync_with_stdio(false);
    cin.tie(0);

    int n, E, T;
    cin >> n >> E >> T;

    vector<int> X(n + 1, 0);
    for (int i = 1; i <= n; ++i) {
        cin >> X[i];
    }

    vector<int64_t> dp(n + 1, 0);
    for (int i = 1; i <= n; ++i) {
        dp[i] = 1LL << 62;
        for (int j = i - 1; j >= 0; --j) {
            dp[i] = min(dp[i], dp[j] + X[j + 1] - X[j] + 
                    3LL * (X[i] - X[j + 1]) + max((int64_t) 0, (int64_t) T - 2LL * (X[i] - X[j + 1])));
        }
    }
    int64_t ans = dp[n] + E - X[n];
    cout << ans << '\n';
}