int led_pin1=1;
int led_pin2=2;
int led_pin3=3;
void setup()
{
  pinMode(led_pin1, OUTPUT);
  pinMode(led_pin2, OUTPUT);
  pinMode(led_pin3, OUTPUT);}
  void loop()
  {
    digitalWrite(led_pin1, HIGH);
    delay(5000);
    digitalWrite(led_pin1, LOW);
    digitalWrite(led_pin2, HIGH);
    delay(5000);
    digitalWrite(led_pin2,LOW);
    digitalWrite(led_pin3, HIGH);
    delay(5000);
    digitalWrite(led_pin3,LOW);


  }