#pragma comment(linker, "/STACK:65777216")
#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <set>
#include <stack>
#include <map>
#include <queue>
#include <string>
#include <memory.h>
#include <iterator>
#define y1 trololoy1
#define y0 trololoy0
#define mem(A,X) memset(A,X,sizeof(A))
#define memo(A) memset(A,0,sizeof(A))
#define forn(I,B) for (int I=1;I<=(B);I++)
#define forg(H,V) for (int H=first[V];h;h=next[H])
#define rep(I,B) for (int I=0;I<(B);I++)
#define labs(X) (((X)>0)?(X):(-(X)))
#define ropen(X) freopen(X,"r",stdin)
#define wopen(X) freopen(X,"w",stdout)
#define rwopen(X) freopen(X".in","r",stdin);freopen(X".out","w",stdout)
#define pb push_back
#define mp make_pair
#define all(X) (X).begin(),(X).end()
#define sqr(X) ((X)*(X))

using namespace std;

typedef pair <int,int> pii;
typedef double ld;
typedef long long ll;
typedef pair <ll,ll> pll;
typedef vector<int> vi;
const int N=1111;
const ll INF=9187201950435737472ll;
const double eps=1e-9;
const double pi=3.14159265358979;

ll f[N][N],ans,mx[N],c;
int a[N],l,r,n,m,w;

inline void build(int num){
    mem(mx,128);
    rep(i,n) mx[i]=f[num][i]-c*a[i];
}

inline ll get_max(int l,int r){
    ll ans=-INF;
    for (int i=l;i<=r;i++) ans>?=mx[i];
    return ans;
}

int main(){
    ropen("input.txt");
    wopen("output.txt");
    scanf("%d%d%d%d%d",&n,&m,&l,&r,&w);
    rep(i,n) scanf("%d",&a[i]);
    mem(f,128);
    rep(i,n) if (a[i]>=l && a[i]<=r) f[1][i]=0;
    for (int i=2;i<=m;i++){
        c=(i-1)*(m-i+1);
        build(i-1);
        int L=0,R=0;
        rep(j,n){
            if (a[j]-a[L]<l) continue;
            while (a[j]-a[L]>r && L<j) ++L;
            if (L==j) continue;
            while (a[j]-a[R+1]>=l && R<j-1) ++R;
            ll t=get_max(L,R);
            if (t<=-INF) f[i][j]=-INF;
            else f[i][j]=t+c*a[j];
        }
    }
    rep(i,n) if (w-a[i]>=l && w-a[i]<=r) ans>?=f[m][i];
    printf("%I64d\n",ans+ans);
    return 0;
}