There are five people: A, B, C, D, and E. When A, B, and C are placed before D and E, find the number of cases in which 5 people can line up in order.
[OP_LIST_SOL] A B C D E [OP_LIST_EOL] [OP_LIST_SOL] A B C [OP_LIST_EOL] [OP_LIST_LEN] [OP_LIST_LEN] [OP_PERM]
var_a = 'A'
var_b = 'B'
var_c = 'C'
var_d = 'D'
var_e = 'E'
list_a= []
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_f = 'A'
var_g = 'B'
var_h = 'C'
list_b= []
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)
if "/" in str(var_f):
    var_f = eval(str(var_f))
list_b.append(var_f)
list_b.reverse()
var_i = len(list_b)
var_j = len(list_b)
var_k = 1
var_i = int(var_i)
var_j = int(var_j)
for i, elem in enumerate(range(var_j)):
    var_k = var_k * (var_i-i)
print(int(var_k))