int redLEDPin = 2;
int yellowLEDPin = 4;
int greenLEDPin = 6;
int blueLEDPin = 8;

void setup() {
  // put your setup code here, to run once:
  pinMode(redLEDPin, OUTPUT);
  pinMode(yellowLEDPin, OUTPUT);
  pinMode(greenLEDPin, OUTPUT);
  pinMode(blueLEDPin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(redLEDPin, HIGH);
digitalWrite(yellowLEDPin, HIGH);
digitalWrite(greenLEDPin, HIGH);
digitalWrite(blueLEDPin, HIGH);

delay(1000);

digitalWrite(redLEDPin, LOW);
digitalWrite(yellowLEDPin, LOW);
digitalWrite(greenLEDPin, LOW);
digitalWrite(blueLEDPin, LOW);

delay(1000);
}