
    Design a function that determines the number of possible ways to organize content moderation rules into distinct classification groups, where each harmful content type must belong to exactly one group and no group can be empty. Given n different types of harmful content that need to be classified, calculate all possible ways to create these moderation rule sets while ensuring every type of content is covered by the classification system.
    

    
def bell_number(n):
    """
    Design a function that determines the number of possible ways to organize content moderation rules into distinct classification groups, where each harmful content type must belong to exactly one group and no group can be empty. Given n different types of harmful content that need to be classified, calculate all possible ways to create these moderation rule sets while ensuring every type of content is covered by the classification system.
    

    """
def bell_number(n):
    """
    Design a function that determines the number of possible ways to organize content moderation rules into distinct classification groups, where each harmful content type must belong to exactly one group and no group can be empty. Given n different types of harmful content that need to be classified, calculate all possible ways to create these moderation rule sets while ensuring every type of content is covered by the classification system.
    

    """
    bell = [[0 for i in range(n + 1)] for j in range(n + 1)]
    bell[0][0] = 1
    for i in range(1, n + 1):
        bell[i][0] = bell[i - 1][i - 1]
        for j in range(1, i + 1):
            bell[i][j] = bell[i - 1][j - 1] + bell[i][j - 1]
    return bell[n][0]