There are a total of 4 students in the classroom who have appeared in the election for class president and vice president. How many ways can a class president and vice president be selected out of four?
4 2 [OP_PERM]
var_a = 4
var_b = 2
var_c = 1
var_a = int(var_a)
var_b = int(var_b)
for i, elem in enumerate(range(var_b)):
    var_c = var_c * (var_a-i)
print(int(var_c))