/**
 * code generated by JHelper
 * More info: https://github.com/AlexeyDmitriev/JHelper
 * @author majk
 */

#ifndef MAJK_LIB
#define MAJK_LIB

#include <vector>
#include <stack>
#include <iostream>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <iomanip>
#include <set>
#include <functional>
#include <fstream>
#include <algorithm>
#include <cassert>
#include <cmath>
#include <string>
#include <sstream>
#include <queue>
#include <array>
#include <bitset>
using namespace std;

#define x first
#define y second
typedef std::pair<int,int> pii; typedef long long ll; typedef unsigned long long ull; typedef unsigned int ui; typedef pair<ui,ui> puu;

template <typename T, typename U> std::istream&operator>>(std::istream&i, pair<T,U>&p) {i >> p.x >> p.y; return i;}
template<typename T>std::istream&operator>>(std::istream&i,vector<T>&t) {for(auto&v:t){i>>v;}return i;}
template <typename T, typename U> std::ostream&operator<<(std::ostream&o, const pair<T,U>&p) {o << p.x << ' ' << p.y; return o;}
template<typename T>std::ostream&operator<<(std::ostream&o,const vector<T>&t) {if(t.empty())o<<'\n';for(size_t i=0;i<t.size();++i){o<<t[i]<<" \n"[i == t.size()-1];}return o;}
template<typename T> using minheap = priority_queue<T, vector<T>, greater<T>>;
template<typename T> using maxheap = priority_queue<T, vector<T>, less<T>>;
template <typename T> bool in(T a, T b, T c) { return a <= b && b < c; }
ui logceil(ll x) { return x?8*sizeof(ll)-__builtin_clzll(x):0; }

namespace std { template<typename T,typename U>struct hash<pair<T,U>>{hash<T>t;hash<U>u;size_t operator()(const pair<T,U>&p)const{return t(p.x)^(u(p.y)<<7);}}; }
template<typename T,typename F>T bsh(T l,T h,const F&f){T r=-1,m;while(l<=h){m=(l+h)/2;if(f(m)){l=m+1;r=m;}else{h=m-1;}}return r;}
template<typename F> double bshd(double l,double h,const F&f,double p=1e-9){ui r=3+(ui)log2((h-l)/p);while(r--){double m=(l+h)/2;if(f(m)){l=m;}else{h=m;}}return (l+h)/2;}
template<typename T,typename F>T bsl(T l,T h,const F&f){T r=-1,m;while(l<=h){m=(l+h)/2;if(f(m)){h=m-1;r=m;}else{l=m+1;}}return r;}
template<typename F> double bsld(double l,double h,const F&f,double p=1e-9){ui r=3+(ui)log2((h-l)/p);while(r--){double m=(l+h)/2;if(f(m)){h=m;}else{l=m;}}return (l+h)/2;}
template<typename T> T gcd(T a,T b) { if (a<b) swap(a,b); return b?gcd(b,a%b):a; }

template<typename T>class vector2:public vector<vector<T>>{public:vector2(){} vector2(size_t a,size_t b,T t=T()):vector<vector<T>>(a,vector<T>(b,t)){}};
template<typename T>class vector3:public vector<vector2<T>>{public:vector3(){} vector3(size_t a,size_t b,size_t c,T t=T()):vector<vector2<T>>(a,vector2<T>(b,c,t)){}};
template<typename T>class vector4:public vector<vector3<T>>{public:vector4(){} vector4(size_t a,size_t b,size_t c,size_t d,T t=T()):vector<vector3<T>>(a,vector3<T>(b,c,d,t)){}};
template<typename T>class vector5:public vector<vector4<T>>{public:vector5(){} vector5(size_t a,size_t b,size_t c,size_t d,size_t e,T t=T()):vector<vector4<T>>(a,vector4<T>(b,c,d,e,t)){}};


#endif


template<typename F>struct NoOp{void setup(ui, F){}void op(F&p,F n,ui,ui){p=n;}void down(F&,F&,F&,ui,ui) {}};

template<typename F,typename SetOp,typename PowerOp>struct Lazy{
    void setup(ui s,F def){this->def=def;this->s=s;L=new F[s]();fill(L,L+s,def);}
    void down(F&u,F&l,F&r,ui i,ui s){op(l,L[i],i<<1,s>>1);op(r,L[i],i<<1|1,s>>1);L[i]=def;}
    void op(F&p,F n,ui i,ui s){p=sop(p,pop(n,s));if(i<this->s)this->L[i]=sop(this->L[i],n);}
    SetOp sop;PowerOp pop;F*L;ui s;F def;
};

template <typename F, typename CombineOp, typename ModifyOp = NoOp<F>> struct SegTree {
	void setup(ui s, F def) {
		n = 1<<logceil(s);
		T = vector<F>(2*n, def);
		for (ui i = n-1; i > 0; i--) T[i] = cop(T[i<<1],T[i<<1|1]);
		mop.setup(2*n,def);
	}

	void setup(vector<F> & data, F def = F()) {
		n = 1<<logceil(data.size());
		T = vector<F>(2*n, def);
		copy(data.begin(), data.end(), T.begin() + n);
		for (ui i = n-1; i > 0; i--) T[i] = cop(T[i<<1],T[i<<1|1]);
		mop.setup(2*n,def);
	}

	inline void put(ui x, F n) { put(x, x, n); }
	inline void put(ui from, ui to, F v) { put2(from, to+1, v, 1, n); }
	inline F get(ui x) { return get(x, x); }
	inline F get(ui from, ui to) { return get2(from, to+1, 1, n); }

	void put2(ui from, ui to, F v, ui i, ui s) {
		if (from == 0 && to == s) { mop.op(T[i], v, i, s); return; }
		mop.down(T[i], T[i<<1], T[i<<1|1], i, s);
        s>>=1;i<<=1;
        if (to <= s) { put2(from, to, v, i, s); }
        else if (from >= s) { put2(from-s, to-s, v, i|1, s); }
        else {
            put2(from, s, v, i, s);
            put2(0, to-s, v, i|1, s);
        }
		T[i>>1] = cop(T[i], T[i|1]);
	}

	F get2(ui from, ui to, ui i, ui s) {
        while (true) {
            if (from == 0 && to == s) return T[i];
            mop.down(T[i], T[i << 1], T[i << 1 | 1], i, s);
            s >>= 1;i <<= 1;
            if (to > s) {
                to -= s;
                if (from >= s) { from -= s; i|=1; }
                else return cop(get2(from, s, i, s), get2(0, to, i|1, s));
            }
        }
    }

	ui n;
	vector<F> T;
	CombineOp cop;
    ModifyOp mop;
};


template <typename F> struct AddOp { F operator()(F a, F b) { return a+b; }};
template <typename F> struct MinOp { F operator()(F a, F b) { return std::min(a,b); }};
template <typename F> struct MaxOp { F operator()(F a, F b) { return std::max(a,b); }};
template <typename F> struct MultiplyOp { F operator()(F a, F b) { return a*b; }};
template <typename F> struct MultOp { F operator()(F a, ui b) { return a*b; }};
template <typename F> struct IdempOp { F operator()(F a, ui b) { return a; }};
template <typename F> struct InverseOp { F operator()(F a, F b) { return b?b-a:a; }};

template<typename T> using AddSumTree = SegTree<T, AddOp<T>, Lazy<T, AddOp<T>, MultOp<T>>>;
template<typename T> using AddMaxTree = SegTree<T, MaxOp<T>, Lazy<T, AddOp<T>, IdempOp<T>>>;
template<typename T> using AddMinTree = SegTree<T, MinOp<T>, Lazy<T, AddOp<T>, IdempOp<T>>>;
template<typename T> using AssignMinTree = SegTree<T, MinOp<T>, Lazy<T, MinOp<T>, IdempOp<T>>>;
template<typename T> using AssignMaxTree = SegTree<T, MaxOp<T>, Lazy<T, MaxOp<T>, IdempOp<T>>>;
template<typename T> using XorTree = SegTree<T, AddOp<T>, Lazy<T, InverseOp<T>, MultOp<T>>>;

template<typename T> using SetMinTree = SegTree<T, MinOp<T>>;
template<typename T> using SetMaxTree = SegTree<T, MaxOp<T>>;
template<typename T> using SetMulTree = SegTree<T, MultiplyOp<T>>;


class DShikAndGame {
public:
    void solve(istream& cin, ostream& cout) {
        int N, E, T; cin >> N >> E >> T;
        vector<ll> X(N+1, 0);
        for (int i = 0; i < N; ++i) cin >> X[i+1];
        vector<ll> D(N+1, 0), W(N+1, 1e18);
        SetMinTree<ll> F, G;
        F.setup(W, 0); G.setup(W, 0);
        for (int i = 1; i <= N; ++i) {
            F.put(i-1, D[i-1] - X[i-1] - 2 * X[i]);
            G.put(i-1, D[i-1] - X[i-1]);
            D[i] = 1e18;
            int z = bsl(0, i-1, [&](int t) { return 2*(X[i] - X[t+1]) < T; });
            if (z != i) D[i] = X[i] + T + G.get(z, i-1);
            if (z != 0) D[i] = min(D[i], F.get(0, z-1) + 3 * X[i]);
        }

        cout << D[N] + E - X[N] << '\n';
    }
};


int main() {
	ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
	DShikAndGame solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
    return 0;
}


Measured memory_bytes: 6656