def maxSubsetSum(arr):
    length = len(arr)
    # Initialize a solution array (dp) to store the solution
    # to the problem for numbers from index 0 to index i
    # at dp[i]
    dp = [0] * length
    
    # Initialize dp[0] as the first element of the array (or 0) if it is negative
    dp[0] = max(arr[0], 0)
    
    # Stop and return dp[0] if the length of the array is 1
    if length == 1:
        return dp[0]
    
    # Initialize dp[1] as the max of the first element, second element (or 0)
    dp[1] = max(dp[0], arr[1])
    
    # Set dp[1] to the maximum of the previous solution or 2 solutions back + the
    # current value in the array (disallowing adjacent elements to be added to the set)
    for i in range(2, length):
        dp[i] = max(dp[i - 2] + arr[i], dp[i - 1])
        
    # Returning the solution for the whole array (as the last element in the dp array)
    return dp[-1]