/*Four LEDs will glow serially after a 
delay of 1sec and off one by one with FIFO */ 
void setup() {
  for(int i=1;i<5;i++){
    pinMode(i,OUTPUT);
  }
}
void loop() {
  for(int i=1;i<5;i++){
    digitalWrite(i,HIGH);
    delay(1000);
    
}
  for(int i=1;i<5;i++){
    digitalWrite(i,LOW);
    delay(1000);// put your main code here, to run repeatedly:
}
}