// Pin assignments
const int ledPin1 = 13;  // Connect first LED to digital pin 9
const int ledPin2 = 12; // Connect second LED to digital pin 10
const int ledPin3 = 11;
void setup() {
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
   pinMode(ledPin3, OUTPUT);
}

void loop() {
  digitalWrite(ledPin1, HIGH); // Turn on first LED
  digitalWrite(ledPin2, LOW);  // Turn off second LED
  digitalWrite(ledPin3,LOW);
  delay(1000);                 // Wait for 1 second
  
  digitalWrite(ledPin1, LOW);  // Turn off first LED
  digitalWrite(ledPin2, HIGH); // Turn on second LED
  digitalWrite(ledPin3,LOW );
  delay(1000);                 // Wait for 1 second


  digitalWrite(ledPin1, LOW);  // Turn off first LED
  digitalWrite(ledPin2,LOW ); // Turn on second LED
  digitalWrite(ledPin3, HIGH );
  delay(1000);
}