The 20 students in Heesun's class have their own attendance numbers ranging from 1 to 20. Among the students in Heesun's class, the female students numbers are 1, 3, 4, 6, 7, 10, 11, 13, 16, 17, 18, and 20, and the student who is an only child is numbered 1, 4, 5, 8, 11, 14, 17 and 20. Find out the number of students who are female and at the same time, an only child.
[OP_LIST_SOL] 1 3 4 6 7 10 11 13 16 17 18 20 [OP_LIST_EOL] [OP_LIST_SOL] 1 4 5 8 11 14 17 20 [OP_LIST_EOL] [OP_SET_INTERSECT] [OP_LIST_LEN]
var_a = 1
var_b = 3
var_c = 4
var_d = 6
var_e = 7
var_f = 10
var_g = 11
var_h = 13
var_i = 16
var_j = 17
var_k = 18
var_l = 20
list_a= []
if "/" in str(var_l):
    var_l = eval(str(var_l))
list_a.append(var_l)
if "/" in str(var_k):
    var_k = eval(str(var_k))
list_a.append(var_k)
if "/" in str(var_j):
    var_j = eval(str(var_j))
list_a.append(var_j)
if "/" in str(var_i):
    var_i = eval(str(var_i))
list_a.append(var_i)
if "/" in str(var_h):
    var_h = eval(str(var_h))
list_a.append(var_h)
if "/" in str(var_g):
    var_g = eval(str(var_g))
list_a.append(var_g)
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_m = 1
var_n = 4
var_o = 5
var_p = 8
var_q = 11
var_r = 14
var_s = 17
var_t = 20
list_b= []
if "/" in str(var_t):
    var_t = eval(str(var_t))
list_b.append(var_t)
if "/" in str(var_s):
    var_s = eval(str(var_s))
list_b.append(var_s)
if "/" in str(var_r):
    var_r = eval(str(var_r))
list_b.append(var_r)
if "/" in str(var_q):
    var_q = eval(str(var_q))
list_b.append(var_q)
if "/" in str(var_p):
    var_p = eval(str(var_p))
list_b.append(var_p)
if "/" in str(var_o):
    var_o = eval(str(var_o))
list_b.append(var_o)
if "/" in str(var_n):
    var_n = eval(str(var_n))
list_b.append(var_n)
if "/" in str(var_m):
    var_m = eval(str(var_m))
list_b.append(var_m)
list_b.reverse()
list_c = list(set(list_a) & set(list_b))
var_u = len(list_c)
print(int(var_u))