def calculate_szymkiewicz_simpson_coefficient(set_1, set_2):
    """Calculate Szymkiewicz-Simpson coefficient between two sets.

    :param set set_1: set 1
    :param set set_2: set 2
    :return: similarity of the two sets
    :rtype: float
    """
    intersection = len(set_1.intersection(set_2))
    smaller_set = min(len(set_1), len(set_2))

    return intersection / smaller_set