using System;

​

public class Solution {

   public static int Rob(int[] nums) {

        int result = 0;

          if(nums.Length == 0)

          {

              return 0;

          }

          if(nums.Length == 1)

          {

              result = nums[0];

          }

        if(nums.Length == 2)

        {

           result = Math.Max(nums[0],nums[1]);

        }

       if(nums.Length > 2)

       {

          for(int i = 2; i < nums.Length; i++)

          {

            if(i == 2)

            {

            nums[i] = Math.Max(nums[0]+nums[2],nums[1]);

            }

              else

              {

                  nums[i] = Math.Max(nums[i] + nums[i-2] , nums[i] + nums[i-3]);

              }

            result = nums[i];

          }

       }

        return result;

    }

    public static void Main()

    {

        int[] nums = {2,7,9,3,1};

        Console.WriteLine(Rob(nums));

    }

}

​