void setup() 
{
  int led1 = 7, led2 = 8, led3 = 9; //signals to the simularotr where each LED is connected to each pin
  pinMode(led1, OUTPUT); //sends the signal for LED1
  pinMode(led2, OUTPUT); //sends the signal for LED2
  pinMode(led3, OUTPUT); //sends the signal for LED3
}

void loop() 
{
  int led1 = 7, led2 = 8, led3 = 9;
  for (int i = 0; i < 3; i++) // To repeat the sequence 3 times
  {
    digitalWrite(led1, HIGH); //To turn the LEDs on one at the same time. Here is the 1st one. 
    digitalWrite(led2, HIGH); //2nd one
    digitalWrite(led3, HIGH); //3rd one
    delay(500); // delays the simualtion 500 ms or half a second
    digitalWrite(led1, LOW); //To turn the LEDs off one at the same time. Here is the 1st one. 
    digitalWrite(led2, LOW); //2nd one
    digitalWrite(led3, LOW); //3rd one
    delay(500); //This turns the LEDs off for 1/2 a second and repeats 2 more times
  }
  for (int i = 0; i < 2; i++) //this needed so the simulator can prcoess the next set of commands
  {
    digitalWrite(led1, HIGH); //To turn the LED on by itself. Here is the 1st one. 
    delay(300); // separates the blinks by 300 ms
    digitalWrite(led1, LOW);  //To turn the LED off by itself. Here is the 1st one.
    delay(300); // separates the blinks by 300 ms
  }
  for (int i = 0; i < 2; i++) //this needed so the simulator can prcoess the next set of commands
  {
    digitalWrite(led2, HIGH); //To turn the LED on by itself. Here is the 2nd one. 
    delay(300); // separates the blinks by 300 ms
    digitalWrite(led2, LOW);  //To turn the LED off by itself. Here is the 2nd one.
    delay(300); // separates the blinks by 300 ms
  }
  for (int i = 0; i < 2; i++) //this needed so the simulator can prcoess the next set of commands
  {
    digitalWrite(led3, HIGH); //To turn the LED on by itself. Here is the 3rd one.  
    delay(300); // separates the blinks by 300 ms
    digitalWrite(led3, LOW);  //To turn the LED off by itself. Here is the 3rd one.
    delay(300); // separates the blinks by 300 ms
  }
}