int ledPin = 4;


void setup() {
  
  pinMode(ledPin, OUTPUT);
}


void loop() {
  digitalWrite(ledPin, HIGH);  
  delay(1000);                 
  digitalWrite(ledPin, LOW);   
  delay(1000);          
  digitalWrite(ledPin, HIGH);  
  delay(555);                 
  digitalWrite(ledPin, LOW);   
  delay(1000);  
}