void setup() {
 pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
pinMode(6,OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
 digitalWrite(3, HIGH);
digitalWrite(4, HIGH);
digitalWrite(5, HIGH);
digitalWrite(6, HIGH);

digitalWrite(3, HIGH);
delay(1000);
digitalWrite(3, LOW);
delay(1000);
digitalWrite(4, HIGH);
delay(1000);
digitalWrite(4, LOW);
delay(1000);
digitalWrite(5, HIGH);
delay(1000);
digitalWrite(5, LOW);
delay(1000);
digitalWrite(6, HIGH);
delay(1000);
digitalWrite(6, LOW);
delay(1000);
}