There are 6 people: A, B, C, D, E, and F. Find the number of ways in which 3 of them are lined up.
6 3 [OP_PERM]
var_a = 6
var_b = 3
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))