
    Design a function for the assessment system that identifies and totals all pairs of student submission scores up to a given threshold, where each score in a pair, when summed with all proper factors of the other score (excluding itself), equals the other score in the pair. The system will use this to match students whose work demonstrates complementary strengths for peer review partnerships.
    

    
def amicable_numbers_sum(limit):
    """
    Design a function for the assessment system that identifies and totals all pairs of student submission scores up to a given threshold, where each score in a pair, when summed with all proper factors of the other score (excluding itself), equals the other score in the pair. The system will use this to match students whose work demonstrates complementary strengths for peer review partnerships.
    

    """
def amicable_numbers_sum(limit):
    """
    Design a function for the assessment system that identifies and totals all pairs of student submission scores up to a given threshold, where each score in a pair, when summed with all proper factors of the other score (excluding itself), equals the other score in the pair. The system will use this to match students whose work demonstrates complementary strengths for peer review partnerships.
    

    """
    if not isinstance(limit, int):
        return 'Input is not an integer!'
    if limit < 1:
        return 'Input must be bigger than 0!'
    amicables = set()
    for num in range(2, limit + 1):
        if num in amicables:
            continue
        sum_fact = sum([fact for fact in range(1, num) if num % fact == 0])
        sum_fact2 = sum([fact for fact in range(1, sum_fact) if sum_fact % fact == 0])
        if num == sum_fact2 and num != sum_fact:
            amicables.add(num)
            amicables.add(sum_fact2)
    return sum(amicables)