There are 28 notebooks. I gave 1/4 of the 28 books to Yeonju, and 3/7 of the 28 books to Minji. Find how many notebooks are left.
28 1 1/4 [OP_SUB] 3/7 [OP_SUB] [OP_MUL]
var_a = 28
var_b = 1
var_c = 0.25
var_d = var_b - var_c
var_e = 0.42857142857142855
var_f = var_d - var_e
var_g = var_a * var_f
print(int(var_g))