void ISR_mode1(){
  for (int i = 2; i <= 11; i++){
    digitalWrite(i, HIGH);
  }
}

void ISR_mode2(){
  for (int i = 11; i>= 2; i--){
    digitalWrite(i, LOW);
  }
}

void setup() {
  // put your setup code here, to run once:
pinMode(18, INPUT_PULLUP);
pinMode(19, INPUT_PULLUP);

attachInterrupt(digitalPinToInterrupt(18), ISR_mode1, FALLING);
attachInterrupt(digitalPinToInterrupt(19), ISR_mode2, FALLING);

Serial.begin(9600);
for (int i=0; i <= 9; i ++){
  pinMode(i, OUTPUT);
  }
}



void loop() {
  // put your main code here, to run repeatedly:
delay(200);
Serial.println("Red 11 to 3");
  for (int i = 11; i >= 3; i -= 2){
    digitalWrite(i, HIGH);
    delay(200);
  }
Serial.println("Blue 2 to 10");
  for (int i = 2; i <= 10; i += 2){
    digitalWrite(i, HIGH);
    delay(200);
  }
Serial.println("Red 11 to 3");
  for (int i = 11; i >= 3; i -= 2){
    digitalWrite(i, LOW);
    delay(200);
  }
Serial.println("Blue 2 to 10");
  for (int i = 2; i <= 10; i += 2){
    digitalWrite(i, LOW);
    delay(200);
  }
}