After finding and moving to the new planet that supports human life, discussions started on which currency should be used. After long negotiations, Bitcoin was ultimately chosen as the universal currency.

These were the great news for Alice, whose grandfather got into Bitcoin mining in 2013, and accumulated a lot of them throughout the years. Unfortunately, when paying something in bitcoin everyone can see how many bitcoins you have in your public address wallet. 

This worried Alice, so she decided to split her bitcoins among multiple different addresses, so that every address has at most x satoshi (1 bitcoin = 10^8 satoshi). She can create new public address wallets for free and is willing to pay f fee in satoshi per transaction to ensure acceptable speed of transfer. The fee is deducted from the address the transaction was sent from. Tell Alice how much total fee in satoshi she will need to pay to achieve her goal.

Input

First line contains number N (1 ≤ N ≤ 200 000) representing total number of public addresses Alice has.

Next line contains N integer numbers a_i (1 ≤ a_i ≤ 10^9) separated by a single space, representing how many satoshi Alice has in her public addresses.

Last line contains two numbers x, f (1 ≤ f < x ≤ 10^9) representing maximum number of satoshies Alice can have in one address, as well as fee in satoshies she is willing to pay per transaction. 

Output

Output one integer number representing total fee in satoshi Alice will need to pay to achieve her goal.

Example

Input

3
13 7 6
6 2


Output

4

Note

Alice can make two transactions in a following way:

0. 13 7 6 (initial state)

1. 6 7 6 5 (create new address and transfer from first public address 5 satoshies)

2. 6 4 6 5 1 (create new address and transfer from second address 1 satoshi)

Since cost per transaction is 2 satoshies, total fee is 4.
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.InputMismatchException;
import java.util.*;
import java.io.*;
import java.lang.*;
public class Main{
    public static class InputReader {
        private InputStream stream;
        private byte[] buf = new byte[1024];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;
        private BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
     
        public InputReader(InputStream stream) {
            this.stream = stream;
        }
     
        public int read() {
            if (numChars==-1)
                throw new InputMismatchException();
     
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                }
                catch (IOException e) {
                    throw new InputMismatchException();
                }
     
                if(numChars <= 0)
                    return -1;
            }
            return buf[curChar++];
        }
     
        public String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
        public int nextInt() {
            int c = read();
     
            while(isSpaceChar(c))
                c = read();
     
            int sgn = 1;
     
            if (c == '-') {
                sgn = -1;
                c = read();
            }
     
            int res = 0;
            do {
                if(c<'0'||c>'9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
     
            return res * sgn;
        }
     
        public long nextLong() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            long res = 0;
     
            do {
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            while (!isSpaceChar(c));
            return res * sgn;
        }
     
        public double nextDouble() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            double res = 0;
            while (!isSpaceChar(c) && c != '.') {
                if (c == 'e' || c == 'E')
                    return res * Math.pow(10, nextInt());
                if (c < '0' || c > '9')
                    throw new InputMismatchException();
                res *= 10;
                res += c - '0';
                c = read();
            }
            if (c == '.') {
                c = read();
                double m = 1;
                while (!isSpaceChar(c)) {
                    if (c == 'e' || c == 'E')
                        return res * Math.pow(10, nextInt());
                    if (c < '0' || c > '9')
                        throw new InputMismatchException();
                    m /= 10;
                    res += (c - '0') * m;
                    c = read();
                }
            }
            return res * sgn;
        }
     
        public String readString() {
            int c = read();
            while (isSpaceChar(c))
                c = read();
            StringBuilder res = new StringBuilder();
            do {
                res.appendCodePoint(c);
                c = read();
            }
            while (!isSpaceChar(c));
     
            return res.toString();
        }
     
        public boolean isSpaceChar(int c) {
            if (filter != null)
                return filter.isSpaceChar(c);
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }
     
        public String next() {
            return readString();
        }
     
        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);
        }
    }
 
    static long gcd(long a, long b){
        if (a == 0)
            return b;  
        return gcd(b % a, a);  
    }
    static long lcm(long a, long b)  {
        return (a*b)/gcd(a, b);  
    }
    public static void sortbyColumn(int arr[][], int col) 
    { 
        
        Arrays.sort(arr, new Comparator<int[]>() { 
            
          @Override              
          
          public int compare(final int[] entry1,  
                             final int[] entry2) { 
  
            
            if (entry1[col] > entry2[col]) 
                return 1; 
            else
                return -1; 
          } 
        });  
    } 
    static long func(long a[],int size,int s){
        long max1=a[s];
        long maxc=a[s];
        for(int i=s+1;i<size;i++){
            maxc=Math.max(a[i],maxc+a[i]);
            max1=Math.max(maxc,max1);
        }
        return max1;
    }
    public static class Pair<U extends Comparable<U>, V extends Comparable<V>> implements Comparable<Pair<U, V>> {
        public U x;
        public V y;
    
        public Pair(U x, V y) {
            this.x = x;
            this.y = y;
        }
    
        public int hashCode() {
            return (x == null ? 0 : x.hashCode() * 31) + (y == null ? 0 : y.hashCode());
        }
    
        public boolean equals(Object o) {
            if (this == o)
                return true;
            if (o == null || getClass() != o.getClass())
                return false;
            Pair<U, V> p = (Pair<U, V>) o;
            return (x == null ? p.x == null : x.equals(p.x)) && (y == null ? p.y == null : y.equals(p.y));
        }
    
        public int compareTo(Pair<U, V> b) {
            int cmpU = x.compareTo(b.x);
            return cmpU != 0 ? cmpU : y.compareTo(b.y);
        }
    
        public String toString() {
            return String.format("(%s, %s)", x.toString(), y.toString());
        }
    
    }
    static class MultiSet<U extends Comparable<U>> {
        public int sz = 0;
        public TreeMap<U, Integer> t;
 
        public MultiSet() {
            t = new TreeMap<>();
        }
 
        public void add(U x) {
            t.put(x, t.getOrDefault(x, 0) + 1);
            sz++;
        }
 
        public void remove(U x) {
            if (t.get(x) == 1) t.remove(x);
            else t.put(x, t.get(x) - 1);
            sz--;
        }
 
    }
    static void shuffle(int[] a) {
        Random get = new Random();
        for (int i = 0; i < a.length; i++) {
            int r = get.nextInt(a.length);
            int temp = a[i];
            a[i] = a[r];
            a[r] = temp;
        }
    }
    static long myceil(long a, long b){
        return (a+b-1)/b;
    }
    
    static long C(long n,long r){
        long count=0,temp=n;
        long ans=1;
        long num=n-r+1,div=1;
        while(num<=n){
            ans*=num;
            //ans+=MOD;
            ans%=MOD;
            ans*=mypow(div,MOD-2);
            //ans+=MOD;
            ans%=MOD;
            num++;
            div++;
        }
        
        ans+=MOD;
        return ans%MOD;
    }
    static long fact(long a){
        long i,ans=1;
        for(i=1;i<=a;i++){
            ans*=i;
            ans%=MOD;
        }
        return ans%=MOD;
    }
    static void sieve(int n){
        is_sieve[0]=1;
        is_sieve[1]=1;
        int i,j,k;
        for(i=2;i<n;i++){
            if(is_sieve[i]==0){
                sieve[i]=i;
                tr.add(i);
                for(j=i*i;j<n;j+=i){
                    if(j>n||j<0){
                        break;
                    }
                    is_sieve[j]=1;
                    sieve[j]=i;
                }
            }
        }
    }
    static long dist[],dp[];
    static int visited[][];
    static ArrayList<Integer> adj[];
    //static int dp[][][];
    static int R,G,B,MOD=1000000007;
    static int[] par,size;
    static int[] sieve,is_sieve;
    static TreeSet<Integer> tr;
    static char ch[][];
    
    static void calc(int n){
        int i,j;
        dp[n-1]=0;
        if(n>1)
        dp[n-2]=1;
        for(i=n-3;i>=0;i--){
            long ind=n-i-1;
            dp[i]=((ind*(long)mypow(10,ind-1))%MOD+dp[i+1])%MOD;
        }
    }
    static long mypow(long x,long y){
        long temp; 
        if( y == 0) 
            return 1; 
        temp = mypow(x, y/2); 
        if (y%2 == 0) 
            return (temp*temp)%MOD; 
        else
            return ((x*temp)%MOD*(temp)%MOD)%MOD; 
    }
    public static void main(String args[]){
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        PrintWriter w = new PrintWriter(outputStream);
        int t,i,j,tno=0;
        //t=in.nextInt();
        t=1;
        while(t-->0){
            int n=in.nextInt();
            int arr[]=new int[n];
            LinkedList<Integer> li=new LinkedList<>();
            for(i=0;i<n;i++){
                arr[i]=in.nextInt();
                li.add(arr[i]);
            }
            int x,f;
            x=in.nextInt();
            f=in.nextInt();
            long ans=0;
            while(!li.isEmpty()){
                int y=li.pollFirst();
                if(y>x){
                    ans+=myceil(y-x,(x+f));
                }
            }
            w.println((long)f*ans);
        }
        w.close();
    }
}