3rd grade students from Min's school split into 18 15-seater buses to go on a field trip. If 3 seats are empty in each bus, how many 3rd grade students are there at Min's school?
15 3 [OP_SUB] 18 [OP_MUL]
var_a = 15
var_b = 3
var_c = var_a - var_b
var_d = 18
var_e = var_c * var_d
print(int(var_e))