using System;

using System.Collections.Generic;

​

​

​

public class Program

{

    public static void Main()

    {

 Dictionary<int,int> indexToValue = new Dictionary<int,int>();

    Int32.Parse(System.Console.ReadLine());

    string values = System.Console.ReadLine();

    string [] plantValues = values.Split(' ');

    Stack<Tuple<int,int>> plants = new Stack<Tuple<int,int>>();

​

    for(int i=0;i<plantValues.Length;i++)

    {

        indexToValue[i+1]=Int32.Parse(plantValues[i]);

        plants.Push(new Tuple<int, int>(i+1,Int32.Parse(plantValues[i])));

    }

    //iterate over data

    int numberOfDays=0;

    int numEliminated=0;

    Stack<Tuple<int,int>> temp = new Stack<Tuple<int,int>>();

​

    while (true)

    {

        if(plants.Count==0 || plants.Count==1 || numEliminated==-1)

        {

         //Console.WriteLine("Breaking ! Count: "+plants.Count+" Eliminated: "+numEliminated);

          break;

        }

        else

        {

           numEliminated=0;

           while(plants.Count>1)

           {

                var rightPlant = plants.Pop();

                //Console.WriteLine("Left: "+plants.Peek()+" "+"Right "+rightPlant);

                if(indexToValue[rightPlant.Item1]>indexToValue[plants.Peek().Item1])

                {

                   //Console.WriteLine("Dropping :"+rightPlant);

                   numEliminated++;

                }

                else

                {

                  temp.Push(rightPlant);

                }

           }

           //Console.WriteLine("End of round!");

           if(numEliminated==0)

           {

               numEliminated=-1;

               break;

           }

           else

           {

              numberOfDays++;

           }

           //Refill original stack

           while(temp.Count>0)

           {

               plants.Push(temp.Pop());

           }

        }

    }

    System.Console.WriteLine(numberOfDays);

    }

​

} 

​