int var;
void setup() {
  // put your setup code here, to run once:
  for (var = 6; var <= 8; var++) {
    pinMode(var, OUTPUT);
  }
  pinMode(12, INPUT);
  digitalWrite(6, HIGH);
}

void loop() {
  // put your main code here, to run repeatedly:
  if (digitalRead(6) and digitalRead(12)) {
    digitalWrite(6, LOW);
    digitalWrite(7, HIGH);
  }
  if (digitalRead(7) and digitalRead(12)) {
    digitalWrite(7, LOW);
    digitalWrite(8, HIGH);
  }
  if (digitalRead(8) and digitalRead(12)) {
    digitalWrite(8, LOW);
    digitalWrite(6, HIGH);
  }


}