
    Design a personalized learning path calculator that determines the total learning points a student can accumulate when starting from an initial difficulty level. The system breaks down the learning experience into progressively easier sub-tasks, where each subsequent task is reduced by 2 difficulty points from the previous level. The learning path continues until the task difficulty reaches or falls below zero, ensuring students can master concepts through gradual progression. For example, if a student starts at difficulty level 5, they would encounter tasks at levels 5, 3, and 1, accumulating points from each level. Calculate the total learning points a student can earn through this stepped learning approach, where each level contributes its difficulty value to the final score.
    

    
def sum_series(n):
    """
    Design a personalized learning path calculator that determines the total learning points a student can accumulate when starting from an initial difficulty level. The system breaks down the learning experience into progressively easier sub-tasks, where each subsequent task is reduced by 2 difficulty points from the previous level. The learning path continues until the task difficulty reaches or falls below zero, ensuring students can master concepts through gradual progression. For example, if a student starts at difficulty level 5, they would encounter tasks at levels 5, 3, and 1, accumulating points from each level. Calculate the total learning points a student can earn through this stepped learning approach, where each level contributes its difficulty value to the final score.
    

    """
def sum_series(n):
    """
    Design a personalized learning path calculator that determines the total learning points a student can accumulate when starting from an initial difficulty level. The system breaks down the learning experience into progressively easier sub-tasks, where each subsequent task is reduced by 2 difficulty points from the previous level. The learning path continues until the task difficulty reaches or falls below zero, ensuring students can master concepts through gradual progression. For example, if a student starts at difficulty level 5, they would encounter tasks at levels 5, 3, and 1, accumulating points from each level. Calculate the total learning points a student can earn through this stepped learning approach, where each level contributes its difficulty value to the final score.
    

    """
    if n < 1:
        return 0
    else:
        return n + sum_series(n - 2)