*(DP)Buy And Sell Stocks With Transaction Fee - Infinite Transactions Allowed

import java.io.*;
import java.util.*;

public class Main {
    
    public static int stock(int n,int[] price,int fee){
        int pwb = -price[0];
        int pws = 0;
        
        for(int i=1;i<n;i++){
            int npwb = Math.max(pwb,pws-price[i]);
            int npws = Math.max(pws,pwb+price[i]-fee);
            
            pwb = npwb;
            pws = npws;
        }
        
        return pws;
    }

    public static void main(String[] args) throws Exception {
        // write your code here
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int[] price = new int[n];
        for(int i=0;i<n;i++){
            price[i]= sc.nextInt();
        }
        int fee = sc.nextInt();
        
        int ans = stock(n,price,fee);
        System.out.println(ans);
    }

}