
    Design a function for a content moderation system that calculates the number of possible ways to classify n posts into different severity levels, where exactly m posts are ranked as more severe than the post immediately following them in the moderation queue. This calculation is crucial for optimizing the automated content filtering system's ability to properly sequence and prioritize content reviews based on severity patterns.
    

    
def eulerian_num(n, m):
    """
    Design a function for a content moderation system that calculates the number of possible ways to classify n posts into different severity levels, where exactly m posts are ranked as more severe than the post immediately following them in the moderation queue. This calculation is crucial for optimizing the automated content filtering system's ability to properly sequence and prioritize content reviews based on severity patterns.
    

    """
def eulerian_num(n, m):
    """
    Design a function for a content moderation system that calculates the number of possible ways to classify n posts into different severity levels, where exactly m posts are ranked as more severe than the post immediately following them in the moderation queue. This calculation is crucial for optimizing the automated content filtering system's ability to properly sequence and prioritize content reviews based on severity patterns.
    

    """
    if m >= n or n == 0:
        return 0
    if m == 0:
        return 1
    return (n - m) * eulerian_num(n - 1, m - 1) + (m + 1) * eulerian_num(n - 1, m)