#include <iostream>#include <cstring>#include <cstdio>using namespace std;const int MAXN = 100 + 28;int dp[15][MAXN];int workers[15];inline int Min( int a, int b ){    return a<b ? a : b;}int main(){    int N;    int hire, salary, fire;    int maxC;    int i, j, k;    int minC;    while( scanf("%d",&N)!=EOF && N )    {        scanf("%d%d%d", &hire, &salary, &fire);        maxC = -1;        for( i=1;i<=N;i++ )        {            scanf("%d",&workers[i]);            maxC = maxC<workers[i] ? workers[i] : maxC;        }        for( i=workers[1];i<=maxC;i++ )            dp[1][i] = hire*i + salary*i;        for( i=2;i<=N;i++ )        {            for( j=workers[i];j<=maxC;j++ )            {                // 前一个月的任何人数都可以引起下一个月部分人数对应的值的改变                minC = 65552365;                for( k=workers[i-1];k<=maxC;k++ )                {                    if( j>k )                        minC = Min( minC, dp[i-1][k]+(j-k)*hire+j*salary );                    else if( k>=j )                        minC = Min( minC, dp[i-1][k]+(k-j)*fire+j*salary );                }                dp[i][j] = minC;            }        }        minC = 65523365;        for( i=workers[N];i<=maxC;i++ )            minC = Min( minC, dp[N][i] );        printf("%d\n", minC);    }    return 0;}