If there are 3 types of pencils, 2 types of erasers, and 5 types of notebooks, find how many ways there are to buy 1 type of pencil, 1 type of eraser, and 1 type of notebook.
3 2 [OP_MUL] 5 [OP_MUL]
var_a = 3
var_b = 2
var_c = var_a * var_b
var_d = 5
var_e = var_c * var_d
print(int(var_e))