Santa Present Factory

package com.company;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        ArrayDeque<Integer> materialStack = new ArrayDeque<>();
        ArrayDeque<Integer> magicValuesQueue = new ArrayDeque<>();
        TreeMap<String, Integer> toys = new TreeMap<>();

        String[] b = bf.readLine().split(" ");
        String[] m = bf.readLine().split(" ");

        for (String string : b) {
            materialStack.push(Integer.parseInt(string));
        }

        for (String string : m) {
            magicValuesQueue.offer(Integer.parseInt(string));
        }





        while (magicValuesQueue.size()>0 && materialStack.size()>0) {
            int values = magicValuesQueue.peek();
            int boxes = materialStack.peek();
            int product = values * boxes;

            if (product < 0) {
                int result = values + boxes;
                magicValuesQueue.poll();
                materialStack.pop();
                materialStack.push(result);

            }
            else if (boxes == 0 || values == 0) {
                if (boxes == 0) {
                    materialStack.pop();
                }
                if (values == 0) {
                    magicValuesQueue.poll();
                }

            }

            else if (product == 150 || product == 250 || product == 300 || product == 400) {
                String gift ;
                if (product == 150) {
                    gift = "Doll";
                    magicValuesQueue.poll();
                    materialStack.pop();
                    toys.putIfAbsent(gift, 0);
                    toys.put(gift, toys.get(gift) + 1);
                } else if (product == 250) {
                    gift = "Wooden train";
                    magicValuesQueue.poll();
                    materialStack.pop();
                    toys.putIfAbsent(gift, 0);
                    toys.put(gift, toys.get(gift) + 1);
                } else if (product == 300) {
                    gift = "Teddy bear";
                    magicValuesQueue.poll();
                    materialStack.pop();
                    toys.putIfAbsent(gift, 0);
                    toys.put(gift, toys.get(gift) + 1);
                } else  {
                    gift = "Bicycle";
                    magicValuesQueue.poll();
                    materialStack.pop();
                    toys.putIfAbsent(gift, 0);
                    toys.put(gift, toys.get(gift) + 1);
                }
            }
            else if (product>0) {
                magicValuesQueue.poll();
                boxes += 15;
                materialStack.pop();
                materialStack.push(boxes);
            }
        }

        if (toys.containsKey("Doll") && toys.containsKey("Wooden train")){
            System.out.println("The presents are crafted! Merry Christmas!");
        }
        else if (toys.containsKey("Teddy bear") && toys.containsKey("Bicycle")){
            System.out.println("The presents are crafted! Merry Christmas!");
        }
        else {
            System.out.println("No presents this Christmas!");
        }

        if (materialStack.size() > 0) {
            System.out.print("Materials left: ");

            for (int i = 0; i < materialStack.size(); i++) {
                if (i == materialStack.size() - 1) {
                    System.out.println(materialStack.pop());
                } else {
                    System.out.print(materialStack.pop() + ", ");
                    i--;
                }
            }
        }

        if (magicValuesQueue.size() > 0) {
            System.out.print("Magic left: ");
            for (int i = 0; i < magicValuesQueue.size(); i++) {
                if (i == magicValuesQueue.size() - 1) {
                    System.out.println(magicValuesQueue.poll());
                } else {
                    System.out.print(magicValuesQueue.poll() + ", ");
                    i--;
                }
            }
        }

        for (Map.Entry<String, Integer> entry : toys.entrySet()) {
            System.out.println(entry.getKey() + ": " + entry.getValue());
        }
    }
}