struct node{

    int minNum, maxNum;

}

month[15];

int n;

int hire,salary,fire;

int dp[15][505];

int main(){

    int n;

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

        scanf("%d%d%d",&hire,&salary,&fire);

        int maxs=-1;

        rep(i,1,n){

            scanf("%d",&month[i].minNum);

            maxs=max( maxs,month[i].minNum);

        }

        rep(i,1,n){

            month[i].maxNum=maxs;

        }

        mem(dp,inf);

        rep(i,month[1].minNum,month[1].maxNum){

            dp[1][i]=i*(hire+salary);

        }

        rep(i,2,n){

            rep(j,month[i].minNum,month[i].maxNum){ //这个月招人数

                rep(k,month[i-1].minNum,month[i-1].maxNum){ //上个月招人数

                    int dd;

                    if(j>k){

                        dd=(j-k)*hire;

                    }else{

                        dd=(k-j)*fire;

                    }

                    dp[i][j]=min( dp[i][j],dp[i-1][k]+salary*j+dd );

                }

            }

        }

        int ans=inf;

        rep(i,month[n].minNum,month[n].maxNum){

            ans=min( ans,dp[n][i] );

        }

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

    }

    return 0;

}