//global variables
int Number=0; //for counting
int LEDpinR = 12; //for 1/2 pins
int LEDpinY = 13; //for 2/2 pins

  // put your setup code here, to run once:
  void setup() {
Serial.begin(9600);
pinMode(LEDpinR, OUTPUT); //setting the red LED pin as an "out"
pinMode(LEDpinY, OUTPUT); //setting the yellow LED pin as an "out"
  }

  // put your main code here, to run repeatedly:
  void loop() {
digitalWrite(LEDpinR, HIGH);
digitalWrite(LEDpinY, LOW);
Serial.print("Red light ON, Yellow light Off, #: ");
Serial.print(Number);
Number++;
delay(200);
digitalWrite(LEDpinR, LOW);
digitalWrite(LEDpinY, HIGH);
Serial.println("...and now, Red is OFF and Yellow is ON");
delay(200);
  }