void setup() {
pinMode(27, OUTPUT);
pinMode(26, OUTPUT);
pinMode(25, OUTPUT);
}

void loop() {
digitalWrite(27,1);
digitalWrite(26,0);
digitalWrite(25,0);
delay((1000));
digitalWrite(27,0);
digitalWrite(26,1);
digitalWrite(25,0);
delay((500));
digitalWrite(27,0);
digitalWrite(26,0);
digitalWrite(25,1);
delay((500));
}