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

void loop()
 {
 digitalWrite(3, HIGH);
 digitalWrite(4, LOW);
 digitalWrite(5, LOW);
 delay(2000);
 digitalWrite(3, LOW);
 digitalWrite(4, HIGH);
 digitalWrite(5, LOW);
 delay(2000);
 digitalWrite(3, LOW);
 digitalWrite(4, LOW);
 digitalWrite(5, HIGH);
 delay(2000);

}