void setup()

pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
}

void loop()

digitalWrite(5,  HIGH);
digitalWrite(6,  LOW);
digitalWrite(7,  LOW);
delay(1000);
digitalWrite(5,  LOW);
digitalWrite(6,  HIGH);
digitalWrite(7,  LOW);
delay(1000);
digitalWrite(5,  LOW);
digitalWrite(6,  LOW);
digitalWrite(7,  HIGH);
delay(1000);
}