9 is a number that 2 subtracted from the number and added with 4. Find what the number is. 
9 2 [OP_ADD] 4 [OP_SUB]
var_a = 9
var_b = 2
var_c = var_a + var_b
var_d = 4
var_e = var_c - var_d
print(int(var_e))