void setup() {
  // put your setup code here, to run once:

  Serial.begin(9600);

  Serial.print("X = ");
  Serial.println(SP,HEX);
}
void loop() {
  // put your main code here, to run repeatedly:
Serial.print("BEFORE: ");
Serial.println(SP,HEX);
int y = 15;
int z = y;
int g = z + y;
int dsf = z-y;
  Serial.println(dsf+g); //this should make these variables DO something...
  Serial.print(" After = ");
  Serial.println(SP,HEX);
  delay(1000);
}