package com.demo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

public class App {
    public static void main(String[] args) throws IOException {

        List<Integer> glasses = getInput();
        int numberOfRounds = getRounds(glasses);
        System.out.println("brothersInTheBar(glasses) = " + numberOfRounds);
    }

    private static int getRounds(List<Integer> glasses) {
        int roundsCounter = 0;
        List<Integer> stack = new ArrayList<>();

        for (int i = 0; i < glasses.size(); i++) {
            stack.add(glasses.get(i));
            if (stack.size() >= 3) {
                int first = stack.get(stack.size() - 1);
                int second = stack.get(stack.size() - 2);
                int third = stack.get(stack.size() - 3);
                if (first == second && first == third) {
                    stack.remove(stack.size() - 1);
                    stack.remove(stack.size() - 1);
                    stack.remove(stack.size() - 1);
                    roundsCounter++;
                }
            }
        }
        return roundsCounter;
    }

    private static List<Integer> getInput() throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        List<Integer> glasses;
        System.out.println("Enter input using space between numbers or commas: ");
        while (true) {
            try {
                String[] input = reader.readLine().split("[,\\s]+");
                glasses = parseArray(input);
                break;
            } catch (IOException | NumberFormatException e) {
                System.out.println("Wrong input! Please try again.");
            }
        }
        reader.close();
        return glasses;
    }

    private static List<Integer> parseArray(String[] arr) throws NumberFormatException {
        List<Integer> glasses = new ArrayList<>();
        for (String s : arr) {
            glasses.add(Integer.parseInt(s));
        }
        return glasses;
    }
}