#include <cstdio>

#include <cstring>

#include <cmath>

#include <iostream>

#include <algorithm>

#include <queue>

#include <cstdlib>

#include <vector>

#include <set>

#include <map>

#define LL long long

#define mod 1000000007

#define inf 1<<30

#define N 100010

using namespace std;

int dp[][],m[];

int main()

{

    int n;

    while(scanf("%d",&n)&&n)

    {

        int a,b,c;

        scanf("%d%d%d",&a,&b,&c);

        int sum=;

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

        memset(dp,0x3f,sizeof(dp));

        dp[][m[]]=m[]*(a+b);

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

        {

            for(int j=m[i];j<=sum;j++)

            {

                for(int k=m[i-];k<=sum;k++)

                    dp[i][j]=min(dp[i-][k]+j*b+(j>k?(j-k)*a:(k-j)*c),dp[i][j]);

            }

        }

        int ans=;

        for(int i=m[n];i<=sum;i++)ans=min(ans,dp[n][i]);

        printf("%d\n",ans);

    }

}