static int maxSubsetSum(int[] arr) {
       for(var i = 2; i < arr.Length; i++){
           arr[i-1] = Math.Max(arr[i-1], arr[i-2]);
           arr[i] = Math.Max(arr[i], Math.Max(arr[i-2], arr[i] + arr[i-2]));
       } 
			 
       return Math.Max(arr[arr.Length - 1], arr[arr.Length - 2]);
    }