const int LED1 = 0;
const int LED2 = 26;
const int LED3 = 1;
const int Switch = 27;

// the setup function runs once when you press reset or power the board
void setup() {
  // initialize digital pin LED_BUILTIN as an output.
  Serial.begin(9600);
  pinMode(LED1, OUTPUT);
  pinMode(LED2, OUTPUT);
  pinMode(LED3, OUTPUT);
  pinMode(Switch, INPUT);
}

// the loop function runs over and over again forever
void loop() {
  int SW = digitalRead(Switch);
  Serial.println(SW);
  
  if (SW == 1) {
    digitalWrite(27, HIGH);  // turn the LED on (HIGH is the voltage level)
    delay(1000);                      // wait for a second
    digitalWrite(0, HIGH);  // turn the LED on (HIGH is the voltage level)
    delay(1000);                      // wait for a second
    digitalWrite(26, HIGH);  // turn the LED on (HIGH is the voltage level)
    delay(1000);                      // wait for a second
    digitalWrite(1, HIGH);  // turn the LED on (HIGH is the voltage level)
    delay(1000);                      // wait for a second
    digitalWrite(0, LOW);   // turn the LED off by making the voltage LOW
    delay(1000);                      // wait for a second
    digitalWrite(26, LOW);   // turn the LED off by making the voltage LOW
    delay(1000);                      // wait for a second
    digitalWrite(1, LOW);   // turn the LED off by making the voltage LOW
    delay(1000);
  }
                       // wait for a second
}