#define LedRed 2
#define LedYellow 3
#define LedGreen 4

void setup() {
  // put your setup code here, to run once:
pinMode(LedRed, OUTPUT);
pinMode(LedYellow, OUTPUT);
pinMode(LedGreen, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(LedRed, HIGH);
delay(1000);
digitalWrite(LedRed, LOW);
delay(1000);
digitalWrite(LedYellow, HIGH);
delay(1000);
digitalWrite(LedYellow, LOW);
delay(1000);
digitalWrite(LedGreen, HIGH);
delay(1000);
digitalWrite(LedGreen, LOW);
delay(1000);
}