using System;

​

public class MainClass

{

    public static void Main()

    {

        int num = Convert.ToInt32(Console.ReadLine());

       string numLine = Console.ReadLine();

       string [] numArray = numLine.Split (' ');

       string array1 = " ";

       string arrayBack = " ";

       for (int i=0;i<num;i++)

       {

           array1 = numArray [i];

       }

       for (int i=num-1; i>=0; i--)

       {

           arrayBack = numArray [i];

       }

       if (array1==arrayBack)

       {

           Console.Write("YES");

       }

       else

       {

           Console.Write("NO");

       }

    }

}