void setup() {
 pinMode(27, OUTPUT);
 pinMode(25, OUTPUT);
 pinMode(12, OUTPUT);
 pinMode(23, OUTPUT);
 pinMode(21, OUTPUT);
 pinMode(19, OUTPUT);
}

void loop() {
 digitalWrite(27, HIGH);
 digitalWrite(25, LOW);
 digitalWrite(12, LOW);
 digitalWrite(23, LOW);
 digitalWrite(21, LOW);
 digitalWrite(19, HIGH);
 delay(1000);

 digitalWrite(27, LOW);
 digitalWrite(25, HIGH);
 digitalWrite(12, LOW);
 digitalWrite(23, LOW);
 digitalWrite(21, HIGH);
 digitalWrite(19, LOW);
 delay(1000);

 digitalWrite(27, LOW);
 digitalWrite(25, LOW);
 digitalWrite(12, HIGH);
 digitalWrite(23, HIGH);
 digitalWrite(21, LOW);
 digitalWrite(19, LOW);
 delay(1000);
}