
    In an adaptive learning system, determine the total number of shared learning milestones between a student's current skill level and their target level, where milestones are represented by the common divisors of both levels. Given a student's current skill level score and a target skill level score, calculate the sum of all values that serve as valid progression points for both levels.
    

    
def sum(a, b):
    """
    In an adaptive learning system, determine the total number of shared learning milestones between a student's current skill level and their target level, where milestones are represented by the common divisors of both levels. Given a student's current skill level score and a target skill level score, calculate the sum of all values that serve as valid progression points for both levels.
    

    """
def sum(a, b):
    """
    In an adaptive learning system, determine the total number of shared learning milestones between a student's current skill level and their target level, where milestones are represented by the common divisors of both levels. Given a student's current skill level score and a target skill level score, calculate the sum of all values that serve as valid progression points for both levels.
    

    """
    sum = 0
    for i in range(1, min(a, b)):
        if a % i == 0 and b % i == 0:
            sum += i
    return sum