There are 28 identical pianos in the music room. Each piano has the same number of keys. When you press the 14th key from the front and the 20th key from the back of a certain piano, find the number of keys on all the pianos in this music room.
14 20 [OP_ADD] 1 [OP_SUB] 28 [OP_MUL]
var_a = 14
var_b = 20
var_c = var_a + var_b
var_d = 1
var_e = var_c - var_d
var_f = 28
var_g = var_e * var_f
print(int(var_g))