Find the sum of the largest and smallest divisors of 15 excluding 1 and itself.
15 [OP_LIST_GET_DIVISOR] 2 [OP_LIST_MAX] 2 [OP_LIST_MIN] [OP_ADD]
var_a = 15
list_a = []
num_sqrt = int(math.sqrt(var_a))
for i in range(1, num_sqrt+1):
    if var_a % i == 0:
        list_a.append(i)
        list_a.append(int(var_a/i))
list_a = sorted(set(list_a))
var_b = 2
list_b=list_a.copy()
list_b.sort()
var_c = list_b[-var_b]
var_d = 2
list_c=list_a.copy()
list_c.sort()
var_e = list_c[var_d-1]
var_f = var_c + var_e
print(int(var_f))