#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
int main(){
	ll n, e, t; cin>>n>>e>>t;
	if(n > 2004) return;
	ll a[n];
	for(int i = 0; i < n; i++) cin>>a[i];
	ll dp[n+1]; dp[n] = 0;
	for(int i = n-1; i >= 0; i--){
		dp[i] = dp[i+1] + t;
		for(int j = i+1; j < n; j++){
			dp[i] = min(dp[i], dp[j+1] + max(2*(a[j]-a[i]), t));
		}
	}
	cout<<dp[0] + e<<endl;
}