using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;

public class Day1
{
	public static void PartA()
    {
        /*
         * Mind the sloppyness of not checking for i, j, k being the same number with the same index in nums! Just wanted to see if this approach was enough and it worked so I never refined it.
         */

        //DAY 1!
        string path = Directory.GetCurrentDirectory() + "input.txt";
        List<int> nums = new List<int>();
        using (StreamReader sr = new StreamReader(path))
        {
            while (sr.Peek() >= 0)
            {
                nums.Add(Int32.Parse(sr.ReadLine()));
            }
        }
        foreach (int i in nums)
        {
            foreach (int j in nums)
            {
                if (i + j == 2020)
                {
                    Console.WriteLine(i * j);
                    return;
                }
            }
        }
    }

    static void PartB()
    {
        //DAY 1!
        string path = Directory.GetCurrentDirectory() + "/input.txt";
        List<int> nums = new List<int>();
        using (StreamReader sr = new StreamReader(path))
        {
            while (sr.Peek() >= 0)
            {
                nums.Add(Int32.Parse(sr.ReadLine()));
            }
        }
        foreach (int i in nums)
        {
            foreach (int j in nums)
            {
                foreach (int k in nums)
                {
                    if (i + j + k == 2020)
                    {
                        Console.WriteLine(i * j * k);
                        return;
                    }
                }
            }
        }
    }
}