
    Given a city divided into n delivery zones during peak traffic hours, determine the number of possible ways to organize delivery routes such that each zone is assigned to exactly one route and all zones are covered. Each route configuration represents a unique way of grouping the delivery zones, where any zone can be combined with any other zone in a route.
    

    
def bell_number(n):
    """
    Given a city divided into n delivery zones during peak traffic hours, determine the number of possible ways to organize delivery routes such that each zone is assigned to exactly one route and all zones are covered. Each route configuration represents a unique way of grouping the delivery zones, where any zone can be combined with any other zone in a route.
    

    """
def bell_number(n):
    """
    Given a city divided into n delivery zones during peak traffic hours, determine the number of possible ways to organize delivery routes such that each zone is assigned to exactly one route and all zones are covered. Each route configuration represents a unique way of grouping the delivery zones, where any zone can be combined with any other zone in a route.
    

    """
    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]