백준 2292 벌집

 

using System;

namespace _2292
{
    class Program
    {
        static void Main(string[] args)
        {
            int input = int.Parse(Console.ReadLine());
            int pdNum = 1;
            int remain = input;
            if(input==1)
            {
                Console.WriteLine(1);
            }
            else
            {
                int ans = 1;
                while (true)
                {
                    if (remain - 6 * pdNum > 1)
                    {
                        remain -= 6 * pdNum;
                        pdNum++;
                    }
                    else
                    {
                        ans = pdNum + 1;
                        break;
                    }
                }
                Console.WriteLine(ans);
            }          
        }
    }
}