import math


def gamma_0(m, rho):
    """
    See p124 immediately after Eq 2.16.

    :param m: int
        number of servers
    :param rho: float
        lambda / (mu * m)
    :return: float

    """

    term1 = 0.24
    term2 = (1 - rho) * (m - 1) * (math.sqrt(4 + 5 * m) - 2 ) / (16 * m * rho)

    return min(term1, term2)