Sanghyun's class donated unread books to the library. There are 20 students in her class and they planned to donate 15 books per student. If the library got 6 books less than they expected, how many books the library got?
15 20 [OP_MUL] 6 [OP_SUB]
var_a = 15
var_b = 20
var_c = var_a * var_b
var_d = 6
var_e = var_c - var_d
print(int(var_e))