The 30 students in Minsu's class have their own attendance numbers from 1 to 30. Among the students in Minsu's class, the students wearing glasses are students 1, 3, 7, 10, 23, and 27, and the students with their hair tied are students 1, 9, 11, 20, and 23. How many students both wear glasses and have their hair tied?
[OP_LIST_SOL] 1 3 7 10 23 27 [OP_LIST_EOL] [OP_LIST_SOL] 1 9 11 20 23 [OP_LIST_EOL] [OP_SET_INTERSECT] [OP_LIST_LEN]
var_a = 1
var_b = 3
var_c = 7
var_d = 10
var_e = 23
var_f = 27
list_a= []
if "/" in str(var_f):
    var_f = eval(str(var_f))
list_a.append(var_f)
if "/" in str(var_e):
    var_e = eval(str(var_e))
list_a.append(var_e)
if "/" in str(var_d):
    var_d = eval(str(var_d))
list_a.append(var_d)
if "/" in str(var_c):
    var_c = eval(str(var_c))
list_a.append(var_c)
if "/" in str(var_b):
    var_b = eval(str(var_b))
list_a.append(var_b)
if "/" in str(var_a):
    var_a = eval(str(var_a))
list_a.append(var_a)
list_a.reverse()
var_g = 1
var_h = 9
var_i = 11
var_j = 20
var_k = 23
list_b= []
if "/" in str(var_k):
    var_k = eval(str(var_k))
list_b.append(var_k)
if "/" in str(var_j):
    var_j = eval(str(var_j))
list_b.append(var_j)
if "/" in str(var_i):
    var_i = eval(str(var_i))
list_b.append(var_i)
if "/" in str(var_h):
    var_h = eval(str(var_h))
list_b.append(var_h)
if "/" in str(var_g):
    var_g = eval(str(var_g))
list_b.append(var_g)
list_b.reverse()
list_c = list(set(list_a) & set(list_b))
var_l = len(list_c)
print(int(var_l))