#include<iostream>
#include<string.h>
#include<algorithm>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define mod 1000000007
#define INF 0x3f3f3f3f
int n;
int people[13];
int dp[13][10000];
int hire,salary,fire;
int main()
{
    while(cin>>n)
    {
        if(n==0) break;
        cin>>hire>>salary>>fire;
        int maxn=0;
        for(int i=1;i<=n;i++)
        {
            cin>>people[i];
            maxn=max(maxn,people[i]);
        }
        memset(dp,INF,sizeof(dp));
        for(int i=people[1];i<=maxn;i++)
        dp[1][i]=i*salary+i*hire;
      for(int i=2;i<=n;i++)
      {
          for(int j=people[i];j<=maxn;j++)
          {
              for(int k=people[i-1];k<=maxn;k++)
              {
                  if(k<=j)
                  dp[i][j]=min(dp[i][j],dp[i-1][k]+j*salary+(j-k)*hire);
                  else
                  dp[i][j]=min(dp[i][j],dp[i-1][k]+j*salary+(k-j)*fire);
              }
          }
      }
      int minn=INF;
      for(int i=people[n];i<=maxn;i++)
      {
          minn=min(minn,dp[n][i]);
      }
      cout<<minn<<endl;
    }
    return 0;
}