int x;
int y;

void setup() {
  // put your setup code here, to run once:
 Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
 xxx(10, 20);
}
void xxx () {
  Serial.println("Hi on screen");
}
int xxx (int a, int b ) {
  return a + b;
}