
    Design a route efficiency calculator that determines the cumulative impact score of a delivery network with n routes, where the impact of each route segment is weighted as 1 divided by its position in the sequence. Calculate this score for n-1 routes to establish a baseline efficiency metric for network optimization.
    

    
def harmonic_sum(n):
    """
    Design a route efficiency calculator that determines the cumulative impact score of a delivery network with n routes, where the impact of each route segment is weighted as 1 divided by its position in the sequence. Calculate this score for n-1 routes to establish a baseline efficiency metric for network optimization.
    

    """
def harmonic_sum(n):
    """
    Design a route efficiency calculator that determines the cumulative impact score of a delivery network with n routes, where the impact of each route segment is weighted as 1 divided by its position in the sequence. Calculate this score for n-1 routes to establish a baseline efficiency metric for network optimization.
    

    """
    if n < 2:
        return 1
    else:
        return 1 / n + harmonic_sum(n - 1)