Ohyoung bought a total of 5 serial magazines from January to May. Find the number of cases in which 5 books are placed in a row on the shelf when the January, March, and May issues are placed on the rightmost shelf in that order. (However, there is only one row of bookshelves.)
5 [OP_LIST_SOL] 1 3 5 [OP_LIST_EOL] [OP_LIST_LEN] [OP_SUB] 5 [OP_LIST_SOL] 1 3 5 [OP_LIST_EOL] [OP_LIST_LEN] [OP_SUB] [OP_PERM]
var_a = 5
var_b = 1
var_c = 3
var_d = 5
list_a= []
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)
list_a.reverse()
var_e = len(list_a)
var_f = var_a - var_e
var_g = 5
var_h = 1
var_i = 3
var_j = 5
list_b= []
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)
list_b.reverse()
var_k = len(list_b)
var_l = var_g - var_k
var_m = 1
var_f = int(var_f)
var_l = int(var_l)
for i, elem in enumerate(range(var_l)):
    var_m = var_m * (var_f-i)
print(int(var_m))