void setup() {
pinMode(2,OUTPUT);// put your setup code here, to run once:
pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
}

void loop() {
digitalWrite(2,HIGH); // put your main code here, to run repeatedly:
digitalWrite(3,LOW);
digitalWrite(4,LOW);
digitalWrite(5,LOW);
delay(500);
digitalWrite(2,LOW);
digitalWrite(3,HIGH);
digitalWrite(4,LOW);
digitalWrite(5,LOW);
delay(500);
digitalWrite(2,LOW);
digitalWrite(3,LOW);
digitalWrite(4,HIGH);
digitalWrite(5,LOW);
delay(500);
digitalWrite(2,LOW);
digitalWrite(3,LOW);
digitalWrite(4,LOW);
digitalWrite(5,HIGH);
delay(500);
}