
    Given a patient taking n different medications prescribed by multiple healthcare providers, determine the number of distinct ways these medications can be grouped together for drug interaction analysis, where each medication must belong to exactly one group and empty groups are not allowed. Each possible grouping arrangement represents a unique way to analyze potential drug interactions between medications within the same group.
    

    
def bell_number(n):
    """
    Given a patient taking n different medications prescribed by multiple healthcare providers, determine the number of distinct ways these medications can be grouped together for drug interaction analysis, where each medication must belong to exactly one group and empty groups are not allowed. Each possible grouping arrangement represents a unique way to analyze potential drug interactions between medications within the same group.
    

    """
def bell_number(n):
    """
    Given a patient taking n different medications prescribed by multiple healthcare providers, determine the number of distinct ways these medications can be grouped together for drug interaction analysis, where each medication must belong to exactly one group and empty groups are not allowed. Each possible grouping arrangement represents a unique way to analyze potential drug interactions between medications within the same group.
    

    """
    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]