const int LED1=7; //LED pin (L)
const int LED2=3; //LED pin (A)
const int LED3=2; //LED pin (U)

void setup() {
  // put your setup code here, to run once:
// initialize digital pin LED1 as an output.
  pinMode(LED1, OUTPUT);
    // put your setup code here, to run once:
// initialize digital pin LED2 as an output.
  pinMode(LED2, OUTPUT);
    // put your setup code here, to run once:
// initialize digital pin LED3 as an output.
  pinMode(LED3, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LED1, HIGH);   // turn the LED1 on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED1, LOW);    // turn the LED1 off by making the voltage LOW
  delay(1000);     

   // put your main code here, to run repeatedly:
  digitalWrite(LED2, HIGH);   // turn the LED1 on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED2, LOW);    // turn the LED1 off by making the voltage LOW
  delay(1000);  

   // put your main code here, to run repeatedly:
  digitalWrite(LED3, HIGH);   // turn the LED1 on (HIGH is the voltage level)
  delay(1000);                       // wait for a second
  digitalWrite(LED3, LOW);    // turn the LED1 off by making the voltage LOW
  delay(1000);  
  digitalWrite(LED1, HIGH);   // turn the LED 1,2 and 3 on (HIGH is the voltage level)
  digitalWrite(LED2, HIGH);
  digitalWrite(LED3, HIGH);
  delay(1000);                       // wait for a second
  digitalWrite(LED1, LOW);    // turn the LED 1,2 and 3 off by making the voltage LOW
  digitalWrite(LED2, LOW);
  digitalWrite(LED3, LOW);
  delay(1000);                       // wait for a second
  

}