#include<cstdio>

 #include<queue>

 #include<algorithm>

 #define maxn 1005

 #define inf 999999

 using namespace std;

 struct node

 {

     int id;

     int v;

     node(int id=,int v=):id(id),v(v){}

     bool operator<(const node &t)const

     {

         return v>t.v;

     }

 };

 priority_queue<node>q1,q2;

 int f[maxn],a[maxn];

 int main()

 {

     int n,c,t1,t2,x;

     while(scanf("%d%d%d%d",&n,&c,&t1,&t2)!=EOF)

     {

         while(!q1.empty())q1.pop();

         while(!q2.empty())q2.pop();

         q1.push(node(,));

         q2.push(node(,));

         for(int i=;i<=n;i++)scanf("%d",&a[i]);

         for(int i=;i<=n;i++)

         {

             while(!q1.empty()&&a[q1.top().id+]+t1<a[i])q1.pop();

             while(!q2.empty()&&a[q2.top().id+]+t2<a[i])q2.pop();

             f[i]=inf;

             if(!q1.empty())f[i]=min(f[i],q1.top().v+t1);

             if(!q2.empty())f[i]=min(f[i],q2.top().v+t2);

             q1.push(node(i,f[i]));

             q2.push(node(i,f[i]));

 //            printf("%d\n",f[i]);

         }

         printf("%d\n",f[n]);

     }

     return ;

 }